Timestamping Vulnerability in rfc3161-client by Trail of Bits

CVE-2025-52556

What is CVE-2025-52556?

The rfc3161-client, a Python library implementing the Time-Stamp Protocol, has a flaw in its timestamp response signature verification logic prior to version 1.0.3. The vulnerability allows an attacker to manipulate timestamp responses, as the library incorrectly verifies the signature of timestamping leaf certificates against the trusted root certificates. This results in the potential for attackers to introduce malicious timestamp response signatures that could bypass validation, undermining the reliability of the timestamping process.

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