CVE-2026-33753
CVE-2026-33753 · Improper Certificate Validation in rfc3161-client
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rfc3161-client is a Python library implementing the Time-Stamp Protocol (TSP) described in RFC 3161. Prior to 1.0.6, an Authorization Bypass vulnerability in rfc3161-client's signature verification allows any attacker to impersonate a trusted TimeStamping Authority (TSA). By exploiting a logic flaw in how the library extracts the leaf certificate from an unordered PKCS#7 bag of certificates, an attacker can append a spoofed certificate matching the target common_name and Extended Key Usage (EKU) requirements. This tricks the library into verifying these authorization rules against the forged certificate while validating the cryptographic signature against an actual trusted TSA (such as FreeTSA), thereby bypassing the intended TSA authorization pinning entirely. This vulnerability is fixed in 1.0.6.
CVSS 6.2 · Moyenne · EPSS 0,2% · Correctif disponible
- Publication
- Mise à jour
Pile logicielle: python
Produits et versions concernés
rfc3161-client
- Versions du logiciel
- < 1.0.6: Concernée
Aucun correctif publié
rfc3161-client PyPI
- Versions du logiciel
- 0.0.2
- 0.0.3
- 0.0.4
- 0.1.0
- 0.1.1
- 0.1.2
- 1.0.0
- 1.0.1
- 1.0.2
- 1.0.3
- 1.0.4
- 1.0.5
- Plages de versions concernées
- ECOSYSTEM: < 1.0.6
Mettez à jour vers 1.0.6