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 timing attack. The verifier may leak information about the correct HMAC when comparing it with the user supplied hash, allowing users to reconstruct the correct HMAC for any data.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2025-16676 | SignXML's signature verification with HMAC is vulnerable to a timing attack |
Github GHSA |
GHSA-gmhf-gg8w-jw42 | SignXML's signature verification with HMAC is vulnerable to a timing 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 16:45:00 +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 timing attack. The verifier may leak information about the correct HMAC when comparing it with the user supplied hash, allowing users to reconstruct the correct HMAC for any data. | |
| Title | SignXML's signature verification with HMAC is vulnerable to a timing attack | |
| Weaknesses | CWE-208 | |
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2025-06-02T16:41:13.270Z
Reserved: 2025-05-29T16:34:07.174Z
Link: CVE-2025-48995
Updated: 2025-06-02T16:41:06.346Z
Status : Awaiting Analysis
Published: 2025-06-02T17:15:41.063
Modified: 2025-06-02T17:32:17.397
Link: CVE-2025-48995
No data.
OpenCVE Enrichment
No data.
EUVD
Github GHSA