{"id":"AZL-97941","summary":"CVE-2026-63076 affecting package openssl 3.3.7-4","details":"Issue summary: OpenSSL CMP password based protection verification only\nchecks whether the protectionAlg parameter was not NULL and not its\nASN.1 type, before treating it as a PBMParameter. A crafted message can\ncontain a parameter of a different type, which is then dereferenced as an\ninvalid pointer.\n\nImpact summary: A remote, unauthenticated attacker can crash an application\nacting as a CMP server that accepts PBM-protected messages, or a CMP client\ntalking to a malicious or intercepted CMP server, resulting in a Denial of\nService.\n\nCWE: CWE-476: NULL Pointer Dereference\n\nDescription: When verifying the password-based MAC protection of a CMP\nmessage, OpenSSL library reads the protectionAlg algorithm parameter with\nX509_ALGOR_get0(), which returns both the parameter type and its value\npointer. The value is then cast to an ASN1_STRING and treated as the\nexpected PBMParameter after only checking that pointer is not NULL. The\nparameter type returned by X509_ALGOR_get0() was never consulted.\n\nThis happens during protection verification, before any MAC is computed, so\nno knowledge of the PBM shared secret is required; the only precondition is\nthat PBM verification is reachable. On the server side this is reached from\nOSSL_CMP_SRV_process_request() for any application that stands up a CMP\nserver accepting PBM-protected messages, and on the client side from CMP\nresponse validation against a malicious or on-path (MITM) server. The\nreliable consequence is a denial of service; there is no memory disclosure,\nno controlled memory write, and no path to code execution. CMP is a\nspecialized feature that an application must explicitly enable.\n\nFIPS impact: no\nAs the CMP code lives outside the FIPS module boundary, no FIPS modules\nare affected by this CVE.","modified":"2026-08-29T05:27:27Z","published":"2026-08-25T13:19:26Z","upstream":["CVE-2026-63076"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63076"}],"affected":[{"package":{"name":"openssl","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/openssl"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.3.7-4"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-97941.json"}}],"schema_version":"1.9.0"}