{"id":"CVE-2026-44905","state":"PUBLISHED","title":"Vanetza: Remote Denial of Service via Uncaught OER Encoding Exception in Cryptographic Verification","description":"Vanetza is an open-source implementation of the ETSI C-ITS protocol suite. In 26.02 and earlier, a denial-of-service vulnerability was identified in the cryptographic verification pipeline of Vanetza. When processing incoming V2X messages, the ASN.1 decoder accepts the structure as syntactically valid. However, this reveals a logic-based protocol failure where semantic constraints on specific fields are only strictly enforced during OER re-encoding. Specifically, if a crafted packet contains a certificate where the Psid (Provider Service Identifier) sub-type violates subtype constraints (e.g., out-of-range or invalid CHOICE variant), it is accepted during initial parsing, where subtype constraints are not enforced. Later, when StraightVerifyService attempts to calculate a message hash for cryptographic verification, it must re-encode the signing certificate. The underlying ASN.1 wrapper (asn1c_wrapper.cpp) detects the semantic violation during encoding and raises a std::runtime_error. This exception is not caught within the encoding path and propagates to std::terminate, resulting in immediate process termination. This vulnerability is fixed with commit e1a2e2709210d309458c3d77f98d50dec26c0df0.","publishedAt":"2026-05-26T21:18:33.445Z","updatedAt":"2026-05-27T13:01:57.541Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["riebl vanetza"],"affected":[{"vendor":"riebl","product":"vanetza","versions":[{"version":"< e1a2e2709210d309458c3d77f98d50dec26c0df0","status":"affected"},{"version":"<= 26.02","status":"affected"}]}],"references":["https://github.com/riebl/vanetza/security/advisories/GHSA-q9fq-3rx9-7xcv","https://github.com/riebl/vanetza/commit/e1a2e2709210d309458c3d77f98d50dec26c0df0"],"weaknesses":["CWE-248"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/44xxx/CVE-2026-44905.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-44905","state":"PUBLISHED","datePublished":"2026-05-26T21:18:33.445Z","dateUpdated":"2026-05-27T13:01:57.541Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-07T21:50:33.547Z"},"containers":{"cna":{"title":"Vanetza: Remote Denial of Service via Uncaught OER Encoding Exception in Cryptographic Verification","descriptions":[{"lang":"en","value":"Vanetza is an open-source implementation of the ETSI C-ITS protocol suite. In 26.02 and earlier, a denial-of-service vulnerability was identified in the cryptographic verification pipeline of Vanetza. When processing incoming V2X messages, the ASN.1 decoder accepts the structure as syntactically valid. However, this reveals a logic-based protocol failure where semantic constraints on specific fields are only strictly enforced during OER re-encoding. Specifically, if a crafted packet contains a certificate where the Psid (Provider Service Identifier) sub-type violates subtype constraints (e.g., out-of-range or invalid CHOICE variant), it is accepted during initial parsing, where subtype constraints are not enforced. Later, when StraightVerifyService attempts to calculate a message hash for cryptographic verification, it must re-encode the signing certificate. The underlying ASN.1 wrapper (asn1c_wrapper.cpp) detects the semantic violation during encoding and raises a std::runtime_error. This exception is not caught within the encoding path and propagates to std::terminate, resulting in immediate process termination. This vulnerability is fixed with commit e1a2e2709210d309458c3d77f98d50dec26c0df0."}],"affected":[{"vendor":"riebl","product":"vanetza","versions":[{"version":"< e1a2e2709210d309458c3d77f98d50dec26c0df0","status":"affected"},{"version":"<= 26.02","status":"affected"}]}],"references":[{"url":"https://github.com/riebl/vanetza/security/advisories/GHSA-q9fq-3rx9-7xcv","name":"https://github.com/riebl/vanetza/security/advisories/GHSA-q9fq-3rx9-7xcv","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/riebl/vanetza/commit/e1a2e2709210d309458c3d77f98d50dec26c0df0","name":"https://github.com/riebl/vanetza/commit/e1a2e2709210d309458c3d77f98d50dec26c0df0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-248","lang":"en","description":"CWE-248: Uncaught Exception","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-26T21:18:33.445Z"},"source":{"advisory":"GHSA-q9fq-3rx9-7xcv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/riebl/vanetza/security/advisories/GHSA-q9fq-3rx9-7xcv","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-27T13:01:15.575636Z","id":"CVE-2026-44905","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-27T13:01:57.541Z"}}]}}}