CVE-2025-48994

SignXML is an implementation of the W3C XML Signature standard in Python. When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), versions of SignXML prior to 4.0.4 are vulnerable to a potential algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.

SignXML is an implementation of the W3C XML Signature standard in Python. When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), versions of SignXML prior to 4.0.4 are vulnerable to a potential algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with SignXML 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.

When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), prior versions of SignXML are vulnerable to a potential algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with signxml 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.

When verifying signatures with X509 certificate validation turned off and HMAC shared secret set (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), prior versions of SignXML are vulnerable to a potential algorithm confusion attack. Unless the user explicitly limits the expected signature algorithms using the `signxml.XMLVerifier.verify(expect_config=...)` setting, an attacker may supply a signature unexpectedly signed with a key other than the provided HMAC key, using a different (asymmetric key) signature algorithm. Starting with signxml 4.0.4, specifying `hmac_key` causes the set of accepted signature algorithms to be restricted to HMAC only, if not already restricted by the user.

SignXML es una implementación del estándar de firma XML del W3C en Python. Al verificar firmas con la validación de certificado X509 desactivada y el secreto compartido HMAC establecido (`signxml.XMLVerifier.verify(require_x509=False, hmac_key=...`), las versiones de SignXML anteriores a la 4.0.4 son vulnerables a un posible ataque de confusión de algoritmos. A menos que el usuario limite explícitamente los algoritmos de firma esperados mediante la opción `signxml.XMLVerifier.verify(expect_config=...)`, un atacante podría proporcionar una firma firmada inesperadamente con una clave distinta a la clave HMAC proporcionada, utilizando un algoritmo de firma diferente (clave asimétrica). A partir de SignXML 4.0.4, especificar `hmac_key` limita el conjunto de algoritmos de firma aceptados a HMAC únicamente, si el usuario no lo ha hecho ya.