CWE-122

Heap-based buffer overflow in Adobe Flash Player before 13.0.0.296 and 14.x through 18.x before 18.0.0.194 on Windows and OS X and before 11.2.202.468 on Linux allows remote attackers to execute arbitrary code via unspecified vectors, as exploited in the wild in June 2015.

Libarchive Remote Code Execution Vulnerability

A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. This flaw allows a remote attacker, who can create valid DNS replies, to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in sort_rrset() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Heap-based buffer overflow in Adobe Reader and Acrobat 7.x before 7.1.4, 8.x before 8.1.7, and 9.x before 9.2 allows remote attackers to execute arbitrary code via a crafted PDF file that triggers memory corruption, as exploited in the wild in October 2009. NOTE: some of these details are obtained from third party information.

Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by a heap-based buffer overflow vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

A heap-based buffer overflow vulnerability [CWE-122] in FortiOS version 7.2.4 and below, version 7.0.11 and below, version 6.4.12 and below, version 6.0.16 and below and FortiProxy version 7.2.3 and below, version 7.0.9 and below, version 2.0.12 and below, version 1.2 all versions, version 1.1 all versions SSL-VPN may allow a remote attacker to execute arbitrary code or commands via specifically crafted requests.

A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in the way RRSets are sorted before validating with DNSSEC data. An attacker on the network, who can forge DNS replies such as that they are accepted as valid, could use this flaw to cause a buffer overflow with arbitrary data in a heap memory segment, possibly executing code on the machine. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

An exploitable code execution vulnerability exists in the rendering functionality of Nitro Pro 13.13.2.242 and 13.16.2.300. When drawing the contents of a page and selecting the stroke color from an 'ICCBased' colorspace, the application will read a length from the file and use it as a loop sentinel when writing data into the member of an object. Due to the object member being a buffer of a static size allocated on the heap, this can result in a heap-based buffer overflow. A specially crafted document must be loaded by a victim in order to trigger this vulnerability.

Windows Remote Desktop Licensing Service Remote Code Execution Vulnerability

Redis is an in-memory database that persists on disk. In Redit 7.0 prior to 7.0.12, extracting key names from a command and a list of arguments may, in some cases, trigger a heap overflow and result in reading random heap memory, heap corruption and potentially remote code execution. Several scenarios that may lead to authenticated users executing a specially crafted `COMMAND GETKEYS` or `COMMAND GETKEYSANDFLAGS`and authenticated users who were set with ACL rules that match key names, executing a specially crafted command that refers to a variadic list of key names. The vulnerability is patched in Redis 7.0.12.

Adobe ColdFusion versions Update 14 (and earlier) and Update 4 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue does not require user interaction, the vulnerability is triggered when a crafted network packet is sent to the server.

Windows libarchive Remote Code Execution Vulnerability

A heap-based buffer overflow flaw was found in the rsync daemon. This issue is due to improper handling of attacker-controlled checksum lengths (s2length) in the code. When MAX_DIGEST_LEN exceeds the fixed SUM_LENGTH (16 bytes), an attacker can write out of bounds in the sum2 buffer.

A bug affects the Linux kernel’s ksmbd NTLMv2 authentication and is known to crash the OS immediately in Linux-based systems.

A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow

Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

GIMP PSD File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GIMP. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of PSD files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute arbitrary code in the context of the current process. Was ZDI-CAN-22094.

In Eclipse Mosquitto, from version 1.3.2 through 2.0.18, if a malicious broker sends a crafted SUBACK packet with no reason codes, a client using libmosquitto may make out of bounds memory access when acting in its on_subscribe callback. This affects the mosquitto_sub and mosquitto_rr clients.

The vCenter Server contains a heap-overflow vulnerability in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may trigger this vulnerability by sending a specially crafted network packet potentially leading to remote code execution.

Acrobat Reader DC versions 2020.012.20048 (and earlier), 2020.001.30005 (and earlier) and 2017.011.30175 (and earlier) are affected by a heap-based buffer overflow vulnerability in the submitForm function, potentially resulting in arbitrary code execution in the context of the current user. Exploitation requires user interaction in that a victim must open a crafted .pdf file in Acrobat Reader.

A heap buffer overflow in the TFTP receiving code allows for DoS or arbitrary code execution in libcurl versions 7.19.4 through 7.64.1.

Windows Common Log File System Driver Elevation of Privilege Vulnerability

Microsoft Excel Remote Code Execution Vulnerability

Redis is an in-memory database that persists on disk. A specially crafted Lua script executing in Redis can trigger a heap overflow in the cjson library, and result with heap corruption and potentially remote code execution. The problem exists in all versions of Redis with Lua scripting support, starting from 2.6, and affects only authenticated and authorized users. The problem is fixed in versions 7.0.12, 6.2.13, and 6.0.20.

Acrobat Reader DC version 21.007.20099 (and earlier), 20.004.30017 (and earlier) and 17.011.30204 (and earlier) are affected by a heap overflow vulnerability due to insecure handling of a crafted file, potentially resulting in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

A buffer overflow vulnerability in WhatsApp VOIP stack allowed remote code execution via specially crafted series of RTCP packets sent to a target phone number. The issue affects WhatsApp for Android prior to v2.19.134, WhatsApp Business for Android prior to v2.19.44, WhatsApp for iOS prior to v2.19.51, WhatsApp Business for iOS prior to v2.19.51, WhatsApp for Windows Phone prior to v2.18.348, and WhatsApp for Tizen prior to v2.18.15.

DHCP Server Service Remote Code Execution Vulnerability

Adobe ColdFusion versions Update 14 (and earlier) and Update 4 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue does not require user interaction, the vulnerability is triggered when a crafted network packet is sent to the server.

The retr.c:fd_read_body() function is called when processing OK responses. When the response is sent chunked in wget before 1.19.2, the chunk parser uses strtol() to read each chunk's length, but doesn't check that the chunk length is a non-negative number. The code then tries to read the chunk in pieces of 8192 bytes by using the MIN() macro, but ends up passing the negative chunk length to retr.c:fd_read(). As fd_read() takes an int argument, the high 32 bits of the chunk length are discarded, leaving fd_read() with a completely attacker controlled length argument. The attacker can corrupt malloc metadata after the allocated buffer.

A Heap overflow vulnerability in WLInfoRailService component of Ivanti Avalanche before 6.4.3 allows an unauthenticated remote attacker to execute arbitrary commands.

Acrobat Reader DC version 21.007.20099 (and earlier), 20.004.30017 (and earlier) and 17.011.30204 (and earlier) are affected by a heap overflow vulnerability due to insecure handling of a crafted file, potentially resulting in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

A Heap-based buffer overflow vulnerability in the SMA100 series web interface allows remote, unauthenticated attacker to cause Denial of Service (DoS) or potentially results in code execution.

A memory corruption vulnerability in Fluent Bit versions 2.0.7 thru 3.0.3. This issue lies in the embedded http server’s parsing of trace requests and may result in denial of service conditions, information disclosure, or remote code execution.

Microsoft Protected Extensible Authentication Protocol (PEAP) Remote Code Execution Vulnerability

GIMP DDS File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of GIMP. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of DDS files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. . Was ZDI-CAN-22093.

Heap-based Buffer Overflow in GitHub repository vim/vim prior to 8.2.

Microsoft Protected Extensible Authentication Protocol (PEAP) Remote Code Execution Vulnerability

A heap-buffer overflow vulnerability was found in the Redis hyperloglog data structure versions 3.x before 3.2.13, 4.x before 4.0.14 and 5.x before 5.0.4. By carefully corrupting a hyperloglog using the SETRANGE command, an attacker could trick Redis interpretation of dense HLL encoding to write up to 3 bytes beyond the end of a heap-allocated buffer.

Windows Common Log File System Driver Elevation of Privilege Vulnerability

Heap-based buffer overflow in BKCLogSvr.exe in Yokogawa CENTUM CS 3000 R3.09.50 and earlier allows remote attackers to execute arbitrary code via crafted UDP packets.

Squid is a caching proxy for the Web. In versions 6.3 and below, Squid is vulnerable to a heap buffer overflow and possible remote code execution attack when processing URN due to incorrect buffer management. This has been fixed in version 6.4. To work around this issue, disable URN access permissions.

A Heap-based buffer overflow vulnerability in SonicWall SMA100 getBookmarks method allows a remote authenticated attacker to potentially execute code as the nobody user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.

Heap-based buffer overflow in Windows SPNEGO Extended Negotiation allows an unauthorized attacker to execute code over a network.

Rockwell Automation ThinManager ThinServer versions 11.0.0 - 13.0.0 is vulnerable to a heap-based buffer overflow. An attacker could send a specifically crafted TFTP or HTTPS request, causing a heap-based buffer overflow that crashes the ThinServer process. If successfully exploited, this could expose the server to arbitrary remote code execution.

Microsoft Protected Extensible Authentication Protocol (PEAP) Remote Code Execution Vulnerability

Windows Kernel Elevation of Privilege Vulnerability

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Netatalk. Authentication is not required to exploit this vulnerability. The specific flaw exists within the dsi_writeinit function. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-17646.

Heap buffer overflow in the TFTP protocol handler in cURL 7.19.4 to 7.65.3.

A heap overflow flaw was found in the Linux kernel, all versions 3.x.x and 4.x.x before 4.18.0, in Marvell WiFi chip driver. The vulnerability allows a remote attacker to cause a system crash, resulting in a denial of service, or execute arbitrary code. The highest threat with this vulnerability is with the availability of the system. If code execution occurs, the code will run with the permissions of root. This will affect both confidentiality and integrity of files on the system.

Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability

Windows Imaging Component Remote Code Execution Vulnerability

Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability

Redis is an open source, in-memory database that persists on disk. In affected versions specially crafted Lua scripts executing in Redis can cause the heap-based Lua stack to be overflowed, due to incomplete checks for this condition. This can result with heap corruption and potentially remote code execution. This problem exists in all versions of Redis with Lua scripting support, starting from 2.6. The problem is fixed in versions 6.2.6, 6.0.16 and 5.0.14. For users unable to update an additional workaround to mitigate the problem without patching the redis-server executable is to prevent users from executing Lua scripts. This can be done using ACL to restrict EVAL and EVALSHA commands.

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

In Fuji Electric V-Server 4.0.6 and prior, several heap-based buffer overflows have been identified, which may allow an attacker to remotely execute arbitrary code.

TightVNC code version 1.3.10 contains heap buffer overflow in rfbServerCutText handler, which can potentially result code execution.. This attack appear to be exploitable via network connectivity.

TightVNC code version 1.3.10 contains heap buffer overflow in InitialiseRFBConnection function, which can potentially result code execution. This attack appear to be exploitable via network connectivity.

Heap-based Buffer Overflow in GitHub repository vim/vim prior to 8.2.4436.

Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a Buffer Overflow vulnerability when parsing a specially crafted PDF file. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

vCenter Server contains a heap-overflow vulnerability in the implementation of the DCERPC protocol. A malicious actor with network access to vCenter Server may trigger this vulnerability by sending a specially crafted network packet potentially leading to remote code execution.

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

Windows Common Log File System Driver Elevation of Privilege Vulnerability

curl before version 7.61.1 is vulnerable to a buffer overrun in the NTLM authentication code. The internal function Curl_ntlm_core_mk_nt_hash multiplies the length of the password by two (SUM) to figure out how large temporary storage area to allocate from the heap. The length value is then subsequently used to iterate over the password and generate output into the allocated storage buffer. On systems with a 32 bit size_t, the math to calculate SUM triggers an integer overflow when the password length exceeds 2GB (2^31 bytes). This integer overflow usually causes a very small buffer to actually get allocated instead of the intended very huge one, making the use of that buffer end up in a heap buffer overflow. (This bug is almost identical to CVE-2017-8816.)

Kernel Streaming WOW Thunk Service Driver Elevation of Privilege Vulnerability

Acrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by an Heap-based buffer overflow vulnerability in the PDFLibTool component. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

Windows CSC Service Elevation of Privilege Vulnerability

procps-ng before version 3.3.15 is vulnerable to a denial of service in ps via mmap buffer overflow. Inbuilt protection in ps maps a guard page at the end of the overflowed buffer, ensuring that the impact of this flaw is limited to a crash (temporary denial of service).

A heap-based buffer overflow vulnerability was found in the Linux kernel, version kernel-2.6.32, in Marvell WiFi chip driver. A remote attacker could cause a denial of service (system crash) or, possibly execute arbitrary code, when the lbs_ibss_join_existing function is called after a STA connects to an AP.

Windows Lightweight Directory Access Protocol (LDAP) Remote Code Execution Vulnerability

Crafted web server requests may cause a heap-based buffer overflow and could therefore trigger a denial-of- service condition due to a crash in the CODESYS V2 web server prior to V1.1.9.22.

UltraVNC revision 1211 has a heap buffer overflow vulnerability in VNC server code inside file transfer offer handler, which can potentially in result code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1212.

UltraVNC revision 1211 has a heap buffer overflow vulnerability in VNC server code inside file transfer request handler, which can potentially result in code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1212.

UltraVNC revision 1211 has a heap buffer overflow vulnerability in VNC server code inside file transfer handler, which can potentially result code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1212.

WECON LeviStudioU Versions 2019-09-21 and prior are vulnerable to a heap-based buffer overflow, which may allow an attacker to remotely execute code.

A heap-based buffer overflow was discovered in the Linux kernel, all versions 3.x.x and 4.x.x before 4.18.0, in Marvell WiFi chip driver. The flaw could occur when the station attempts a connection negotiation during the handling of the remote devices country settings. This could allow the remote device to cause a denial of service (system crash) or possibly execute arbitrary code.

A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device. For more information about this vulnerability, see the Details ["#details"] section of this advisory.

Adobe Animate version 21.0.3 (and earlier) is affected by a Heap-based Buffer Overflow vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

A flaw was found affecting the Linux kernel before version 4.17. By mmap()ing a FUSE-backed file onto a process's memory containing command line arguments (or environment strings), an attacker can cause utilities from psutils or procps (such as ps, w) or any other program which makes a read() call to the /proc/<pid>/cmdline (or /proc/<pid>/environ) files to block indefinitely (denial of service) or for some controlled time (as a synchronization primitive for other attacks).

Windows Bluetooth Driver Remote Code Execution Vulnerability

Advantech WebAccess Node, Version 8.4.4 and prior, Version 9.0.0. Multiple heap-based buffer overflow vulnerabilities exist caused by a lack of proper validation of the length of user-supplied data, which may allow remote code execution.

rdesktop versions up to and including v1.8.3 contain a Heap-Based Buffer Overflow in function cssp_read_tsrequest() that results in a memory corruption and probably even a remote code execution.

rdesktop versions up to and including v1.8.3 contain a Heap-Based Buffer Overflow in function process_plane() that results in a memory corruption and probably even a remote code execution.

rdesktop versions up to and including v1.8.3 contain a Heap-Based Buffer Overflow in function ui_clip_handle_data() that results in a memory corruption and probably even a remote code execution.

Panasonic FPWIN Pro version 7.3.0.0 and prior allows attacker-created project files to be loaded by an authenticated user causing heap-based buffer overflows, which may lead to remote code execution.

A flaw was found in the Linux kernel. A heap based buffer overflow in mwifiex_uap_parse_tail_ies function in drivers/net/wireless/marvell/mwifiex/ie.c might lead to memory corruption and possibly other consequences.

Heap-based buffer overflow in Windows GDI+ allows an unauthorized attacker to execute code over a network.

Heap buffer overflow in UI in Google Chrome on Android prior to 86.0.4240.185 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.

A flaw was found in samba versions 4.0.0 to 4.5.2. The Samba routine ndr_pull_dnsp_name contains an integer wrap problem, leading to an attacker-controlled memory overwrite. ndr_pull_dnsp_name parses data from the Samba Active Directory ldb database. Any user who can write to the dnsRecord attribute over LDAP can trigger this memory corruption. By default, all authenticated LDAP users can write to the dnsRecord attribute on new DNS objects. This makes the defect a remote privilege escalation.

Internet Connection Sharing (ICS) Remote Code Execution Vulnerability

The xmlNextChar function in libxml2 before 2.9.4 allows remote attackers to cause a denial of service (heap-based buffer over-read) via a crafted XML document.

Adobe InCopy versions 17.2 (and earlier) and 16.4.1 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Adobe InCopy versions 17.2 (and earlier) and 16.4.1 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Adobe InDesign versions 17.2.1 (and earlier) and 16.4.1 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Adobe InDesign versions 17.2.1 (and earlier) and 16.4.1 (and earlier) are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

Out of bounds memory access in V8 in Google Chrome prior to 132.0.6834.83 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)

Curl versions 7.33.0 through 7.61.1 are vulnerable to a buffer overrun in the SASL authentication code that may lead to denial of service.