CWE-757
Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
Extended description
When a security mechanism can be forced to downgrade to use a less secure algorithm, this can make it easier for attackers to compromise the product by exploiting weaker algorithm. The victim might not be aware that the less secure algorithm is being used. For example, if an attacker can force a communications channel to use cleartext instead of strongly-encrypted data, then the attacker could read the channel by sniffing, instead of going through extra effort of trying to decrypt the data using brute force techniques.
Common consequences1
- Access ControlBypass Protection Mechanism
Relationships1
- ChildOfCWE-693
CVEs referencing this CWE25
| CVE | Description | Severity | EPSS | Flags | Modified |
|---|---|---|---|---|---|
| CVE-2020-10135 | Legacy pairing and secure-connections pairing authentication in Bluetooth BR/EDR Core Specification v5.2 and earlier may allow an unauthenticated user to complete authentication without pairing credentials via adjacent access. An unauthenticated, adjacent attacker could impersonate a Bluetooth BR/EDR master or slave to pair with a previously paired remote device to successfully complete the authentication procedure without knowing the link key. | MEDIUM5.4 | 2.39%p82 | PoC | 2024-11-21 |
| CVE-2017-9269 | In libzypp before August 2018 GPG keys attached to YUM repositories were not correctly pinned, allowing malicious repository mirrors to silently downgrade to unsigned repositories with potential malicious content. | NONE | 2.29%p81 | 2024-11-21 | |
| CVE-2021-36326 | Dell EMC Streaming Data Platform, versions prior to 1.3 contain an SSL Strip Vulnerability in the User Interface (UI). A remote unauthenticated attacker could potentially exploit this vulnerability, leading to a downgrade in the communications between the client and server into an unencrypted format. | MEDIUM6.5 | 1.18%p64 | 2024-11-21 | |
| CVE-2025-24154 | An out-of-bounds write was addressed with improved input validation. This issue is fixed in iOS 18.3 and iPadOS 18.3, macOS Sequoia 15.3, macOS Sonoma 14.7.3, macOS Ventura 13.7.3, visionOS 2.3. An attacker may be able to cause unexpected system termination or corrupt kernel memory. | CRITICAL9.1 | 1.09%p61 | 2026-05-21 | |
| CVE-2019-14887 | A flaw was found when an OpenSSL security provider is used with Wildfly, the 'enabled-protocols' value in the Wildfly configuration isn't honored. An attacker could target the traffic sent from Wildfly and downgrade the connection to a weaker version of TLS, potentially breaking the encryption. This could lead to a leak of the data being passed over the network. Wildfly version 7.2.0.GA, 7.2.3.GA and 7.2.5.CR2 are believed to be vulnerable. | CRITICAL9.1 | 1.07%p60 | 2024-11-21 | |
| CVE-2017-9267 | In Novell eDirectory before 9.0.3.1 the LDAP interface was not strictly enforcing cipher restrictions allowing weaker ciphers to be used during SSL BIND operations. | NONE | 1.05%p60 | 2024-11-21 | |
| CVE-2024-4995 | Wapro ERP Desktop is vulnerable to MS SQL protocol downgrade request from a server side, what could lead to an unencrypted communication vulnerable to data interception and modification. This issue affects Wapro ERP Desktop versions before 9.00.0. | CRITICAL9.8 | 0.90%p55 | 2026-04-15 | |
| CVE-2023-2974 | A vulnerability was found in quarkus-core. This vulnerability occurs because the TLS protocol configured with quarkus.http.ssl.protocols is not enforced, and the client can force the selection of the weaker supported TLS protocol. | HIGH8.1 | 0.71%p49 | 2024-11-21 | |
| CVE-2019-16791 | In postfix-mta-sts-resolver before 0.5.1, All users can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy. | MEDIUM5.9 | 0.67%p47 | 2024-11-21 | |
| CVE-2018-25029 | The Z-Wave specification requires that S2 security can be downgraded to S0 or other less secure protocols, allowing an attacker within radio range during pairing to downgrade and then exploit a different vulnerability (CVE-2013-20003) to intercept and spoof traffic. | HIGH8.1 | 0.61%p44 | 2024-11-21 | |
| CVE-2020-16200 | Philips Clinical Collaboration Platform, Versions 12.2.1 and prior, does not properly control the allocation and maintenance of a limited resource, thereby enabling an attacker to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. | MEDIUM6.5 | 0.58%p43 | 2025-06-04 | |
| CVE-2024-20069 | In modem, there is a possible selection of less-secure algorithm during the VoWiFi IKE due to a missing DH downgrade check. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01286330; Issue ID: MSV-1430. | MEDIUM6.5 | 0.57%p43 | 2025-04-25 | |
| CVE-2026-2673 | Issue summary: An OpenSSL TLS 1.3 server may fail to negotiate the expected preferred key exchange group when its key exchange group configuration includes the default by using the 'DEFAULT' keyword. Impact summary: A less preferred key exchange may be used even when a more preferred group is supported by both client and server, if the group was not included among the client's initial predicated keyshares. This will sometimes be the case with the new hybrid post-quantum groups, if the client chooses to defer their use until specifically requested by the server. If an OpenSSL TLS 1.3 server's configuration uses the 'DEFAULT' keyword to interpolate the built-in default group list into its own configuration, perhaps adding or removing specific elements, then an implementation defect causes the 'DEFAULT' list to lose its 'tuple' structure, and all server-supported groups were treated as a single sufficiently secure 'tuple', with the server not sending a Hello Retry Request (HRR) even when a group in a more preferred tuple was mutually supported. As a result, the client and server might fail to negotiate a mutually supported post-quantum key agreement group, such as 'X25519MLKEM768', if the client's configuration results in only 'classical' groups (such as 'X25519' being the only ones in the client's initial keyshare prediction). OpenSSL 3.5 and later support a new syntax for selecting the most preferred TLS 1.3 key agreement group on TLS servers. The old syntax had a single 'flat' list of groups, and treated all the supported groups as sufficiently secure. If any of the keyshares predicted by the client were supported by the server the most preferred among these was selected, even if other groups supported by the client, but not included in the list of predicted keyshares would have been more preferred, if included. The new syntax partitions the groups into distinct 'tuples' of roughly equivalent security. Within each tuple the most preferred group included among the client's predicted keyshares is chosen, but if the client supports a group from a more preferred tuple, but did not predict any corresponding keyshares, the server will ask the client to retry the ClientHello (by issuing a Hello Retry Request or HRR) with the most preferred mutually supported group. The above works as expected when the server's configuration uses the built-in default group list, or explicitly defines its own list by directly defining the various desired groups and group 'tuples'. No OpenSSL FIPS modules are affected by this issue, the code in question lies outside the FIPS boundary. OpenSSL 3.6 and 3.5 are vulnerable to this issue. OpenSSL 3.6 users should upgrade to OpenSSL 3.6.2 once it is released. OpenSSL 3.5 users should upgrade to OpenSSL 3.5.6 once it is released. OpenSSL 3.4, 3.3, 3.0, 1.0.2 and 1.1.1 are not affected by this issue. | MEDIUM6.5 | 0.44%p35 | 2026-06-05 | |
| CVE-2024-23656 | Dex is an identity service that uses OpenID Connect to drive authentication for other apps. Dex 2.37.0 serves HTTPS with insecure TLS 1.0 and TLS 1.1. `cmd/dex/serve.go` line 425 seemingly sets TLS 1.2 as minimum version, but the whole `tlsConfig` is ignored after `TLS cert reloader` was introduced in v2.37.0. Configured cipher suites are not respected either. This issue is fixed in Dex 2.38.0. | HIGH7.5 | 0.44%p35 | 2025-06-03 | |
| CVE-2024-38883 | An issue in Horizon Business Services Inc. Caterease 16.0.1.1663 through 24.0.1.2405 and possibly later versions, allows a remote attacker to perform a Drop Encryption Level attack due to the selection of a less-secure algorithm during negotiation. | CRITICAL9.1 | 0.41%p33 | 2025-05-13 | |
| CVE-2024-8773 | SIMPLE.ERP client is vulnerable to MS SQL protocol downgrade request from a server side, what could lead to an unencrypted communication vulnerable to data interception and modification. This issue affect SIMPLE.ERP from 6.20 to 6.30. Only the 6.30 version received a patch 6.30@a03.9, which make it possible for an administrator to enforce encrypted communication. Versions 6.20 and 6.25 remain unpatched. | NONE | 0.39%p30 | 2026-04-15 | |
| CVE-2022-33160 | IBM Security Directory Suite 8.0.1 uses weaker than expected cryptographic algorithms that could allow an attacker to decrypt highly sensitive information. IBM X-Force ID: 228568. | HIGH7.5 | 0.28%p19 | 2024-11-21 | |
| CVE-2025-10693 | When SmartStart Inclusion fails during the onboarding of a Z-Wave PIR sensor, the sensor will join the network as a non-secure device. This vulnerability exists in Silicon Labs' Z-Wave PIR Sensor Reference design delivered as part of SiSDK v2025.6.0 and v2025.6.1. | NONE | 0.26%p17 | 2026-04-15 | |
| CVE-2025-59270 | psPAS PowerShell module does not explicitly enforce TLS 1.2 within the 'Get-PASSAMLResponse' function during the SAML authentication process. An unauthenticated attacker in a 'Man-in-the-Middle' position could manipulate the TLS handshake and downgrade TLS to a deprecated protocol. Fixed in 7.0.209. | LOW3.1 | 0.22%p13 | 2025-09-30 | |
| CVE-2025-36582 | Dell NetWorker, versions 19.12.0.1 and prior, contains a Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade') vulnerability. An unauthenticated attacker with remote access could potentially exploit this vulnerability, leading to Information disclosure. | HIGH7.5 | 0.22%p12 | 2025-08-14 | |
| CVE-2026-32650 | Anviz CrossChex Standard is vulnerable when an attacker manipulates the TDS7 PreLogin to disable encryption, causing database credentials to be sent in plaintext and enabling unauthorized database access. | HIGH7.5 | 0.21%p11 | 2026-05-04 | |
| CVE-2026-1677 | Zephyr sockets created with `IPPROTO_TLS_1_3` can still negotiate a TLS 1.2 connection when both TLS versions are enabled in Kconfig, because the socket-level protocol selection is not propagated to mbedTLS (e.g. via `mbedtls_ssl_conf_min_tls_version`). The ClientHello advertises both versions and the peer can establish TLS 1.2, so applications that assumed `IPPROTO_TLS_1_3` enforces TLS 1.3 may silently use TLS 1.2 and remain exposed to TLS 1.2-specific weaknesses. As a workaround, the `TLS_CIPHERSUITE_LIST` socket option can be restricted to TLS 1.3-only cipher suites. | MEDIUM5.3 | 0.20%p10 | 2026-05-13 | |
| CVE-2022-23000 | The Western Digital My Cloud Web App [https://os5.mycloud.com/] uses a weak SSLContext when attempting to configure port forwarding rules. This was enabled to maintain compatibility with old or outdated home routers. By using an "SSL" context instead of "TLS" or specifying stronger validation, deprecated or insecure protocols are permitted. As a result, a local user with no privileges can exploit this vulnerability and jeopardize the integrity, confidentiality and authenticity of information transmitted. The scope of impact cannot extend to other components and no user input is required to exploit this vulnerability. | HIGH7.8 | 0.18%p8 | 2024-11-21 | |
| CVE-2026-6550 | Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts. To remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above. | MEDIUM4.7 | 0.10%p1 | 2026-04-24 | |
| CVE-2026-48747 | ### Description `Symfony\Component\Mailer\Bridge\Mailomat\Webhook\MailomatRequestParser::validateSignature()` parses the `X-MOM-Webhook-Signature` request header as `algo=signature` and passes the wire-supplied `$algo` directly to `hash_hmac()` when verifying the request against the configured webhook secret. The request therefore selects the HMAC primitive used to authenticate it. PHP's `hash_hmac()` enforces only that the chosen algorithm is HMAC-compatible. That set still includes primitives with known cryptanalysis (`md4`, `md5`, `ripemd128`, `tiger128,3`, … — e.g. existential forgery of HMAC-MD4, Contini & Yin, ASIACRYPT 2006). This is the canonical algorithm-confusion shape, analogous to JWT `alg=none` / `alg=HS256` downgrades: any future cryptographic weakness in any HMAC primitive PHP exposes becomes immediately exploitable against a Mailomat webhook receiver, the moment an attacker is in a position to compute a signature for that primitive, without a code change on the Symfony side. Mailomat's [documented webhook security](https://api.mailomat.swiss/docs/#tag/webhook-security) pins SHA-256; the parser did not. ### Resolution `MailomatRequestParser::validateSignature()` now requires the signature header to be of the form `sha256=<hex>` and verifies the signature with HMAC-SHA256 keyed by the configured secret using a constant-time comparison. Any other algorithm declared on the wire (including the HMAC primitives PHP would otherwise accept) is rejected. The patch for this issue is available [here](https://github.com/symfony/symfony/commit/bdfe9fe0d94d33dfaca0bc2fe0b00b54767b0c88) for branch 7.4 (and forward-ported to 8.0 and 8.1). ### Credits Symfony would like to thank Omar Alshammari, Essam Alanazi and Alwaleed Alshammari for reporting the issue and Nicolas Grekas for providing the fix. | NONE | no EPSS | 2026-06-15 |