CVE-2026-33753

{"id": "CVE-2026-33753", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-33753", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-08T16:08:28.007589Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.2, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.5}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "trailofbits", "product": "rfc3161-client", "versions": [{"status": "affected", "version": "< 1.0.6"}]}]}], "published": "2026-04-08T16:16:23.670", "references": [{"url": "https://github.com/trailofbits/rfc3161-client/security/advisories/GHSA-3xxc-pwj6-jgrj", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/trailofbits/rfc3161-client/security/advisories/GHSA-3xxc-pwj6-jgrj", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-295"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "rfc3161-client es una biblioteca Python que implementa el Protocolo de Sellado de Tiempo (TSP) descrito en la RFC 3161. Antes de la versi\u00f3n 1.0.6, una vulnerabilidad de omisi\u00f3n de autorizaci\u00f3n en la verificaci\u00f3n de firma de rfc3161-client permite a cualquier atacante suplantar a una Autoridad de Sellado de Tiempo (TSA) de confianza. Al explotar un fallo l\u00f3gico en c\u00f3mo la biblioteca extrae el certificado hoja de una bolsa de certificados PKCS#7 desordenada, un atacante puede a\u00f1adir un certificado falsificado que coincida con los requisitos de common_name y Uso Extendido de Clave (EKU) del objetivo. Esto enga\u00f1a a la biblioteca para que verifique estas reglas de autorizaci\u00f3n contra el certificado falsificado mientras valida la firma criptogr\u00e1fica contra una TSA de confianza real (como FreeTSA), eludiendo as\u00ed por completo el anclaje de autorizaci\u00f3n de TSA previsto. Esta vulnerabilidad est\u00e1 corregida en la versi\u00f3n 1.0.6."}], "lastModified": "2026-07-24T23:10:00.563", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:trailofbits:rfc3161-client:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "16E3C452-B9EE-490C-A46E-F8F8B8BB936A", "versionEndExcluding": "1.0.6"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}