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.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2025-16666 | SignXML's signature verification with HMAC is vulnerable to an algorithm confusion attack |
Github GHSA |
GHSA-6vx8-pcwv-xhf4 | SignXML's signature verification with HMAC is vulnerable to an algorithm confusion attack |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 02 Jun 2025 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 02 Jun 2025 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | SignXML's signature verification with HMAC is vulnerable to an algorithm confusion attack | |
| Weaknesses | CWE-303 | |
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2025-06-02T16:30:51.717Z
Reserved: 2025-05-29T16:34:07.174Z
Link: CVE-2025-48994
Updated: 2025-06-02T16:30:44.282Z
Status : Awaiting Analysis
Published: 2025-06-02T17:15:40.853
Modified: 2025-06-02T17:32:17.397
Link: CVE-2025-48994
No data.
OpenCVE Enrichment
No data.
EUVD
Github GHSA