VDB
CVE-2025-52556
CVE-2025-52556
PUBLISHED
CVSS 9.300000190734863 CRITICAL
rfc3161-client is a Python library implementing the Time-Stamp Protocol (TSP) described in RFC 3161. Prior to version 1.0.3, there is a flaw in the timestamp response signature verification logic. In particular, chain verification is performed against the TSR's embedded certificates up to the trusted root(s), but fails to verify the TSR's own signature against the timestamping leaf certificates. Consequently, vulnerable versions perform insufficient signature validation to properly consider a TSR verified, as the attacker can introduce any TSR signature so long as the embedded leaf chains up to some root TSA. This issue has been patched in version 1.0.3. There is no workaround for this issue.
EPSS 0.15% · 4.2th percentile
Risk Scores
CVSS 4.0
9.300000190734863
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS Score
0.15%
4.2th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| PyPI | rfc3161-client | 0 |
| trailofbits | rfc3161-client | * |
Timeline
- Jan 21, 1970 Security Advisory
- Jun 20, 2025 CVE Published
- Jun 21, 2025 EPSS Score
- Jun 21, 2025 Coalition ESS Score
- Jun 21, 2025 PoC Published
- Jun 23, 2025 Coalition ESS Score
- Jul 1, 2025 EPSS Score
- Jul 11, 2025 EPSS Score
- Jul 22, 2025 EPSS Score
- Aug 1, 2025 EPSS Score
- Aug 11, 2025 EPSS Score
- Aug 21, 2025 EPSS Score