{"cve":"CVE-2021-46837","nvd":{"published":"2022-08-30T07:15:07.417","modified":"2026-06-17T04:15:38.630","status":"Modified","description":"res_pjsip_t38 in Sangoma Asterisk 16.x before 16.16.2, 17.x before 17.9.3, and 18.x before 18.2.2, and Certified Asterisk before 16.8-cert7, allows an attacker to trigger a crash by sending an m=image line and zero port in a response to a T.38 re-invite initiated by Asterisk. This is a re-occurrence of the CVE-2019-15297 symptoms but not for exactly the same reason. The crash occurs because there is an append operation relative to the active topology, but this should instead be a replace operation.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-476"],"references":["https://downloads.asterisk.org/pub/security/AST-2021-006.html","https://lists.debian.org/debian-lts-announce/2022/11/msg00021.html","https://www.debian.org/security/2022/dsa-5285","https://downloads.asterisk.org/pub/security/AST-2021-006.html","https://lists.debian.org/debian-lts-announce/2022/11/msg00021.html"],"products":["asterisk:certified_asterisk","debian:debian_linux","digium:asterisk"],"source":"nvd","synced_at":"2026-10-19T21:35:14.992143698+00:00"},"epss":{"cve":"CVE-2021-46837","score":0.0467,"percentile":0.91764,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}