What’s Vulnerable › Vulnerabilities
CVE-2025-49832: Asterisk is Vulnerable to Remote DoS and possible RCE Attacks During Memory Allocation
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2025-08-01 · updated 2026-06-17
- Weakness: CWE-476
Description
Asterisk is an open source private branch exchange and telephony toolkit. In versions up to and including 18.26.2, between 20.00.0 and 20.15.0, 20.7-cert6, 21.00.0, 22.00.0 through 22.5.0, there is a remote DoS and possible RCE condition in `asterisk/res/res_stir_shaken /verification.c` that can be exploited when an attacker can set an arbitrary Identity header, or STIR/SHAKEN is enabled, with verification set in the SIP profile associated with the endpoint to be attacked. This is fixed in versions 18.26.3, 20.7-cert6, 20.15.1, 21.10.1 and 22.5.1.
Affected products
- asterisk: before 18.26.3; from 20.0.0 before 20.15.1; from 21.0.0 before 21.10.1; from 22.0.0 before 22.5.1 — fixed in 18.26.3, 20.15.1, 21.10.1, 22.5.1
- Sangoma Certified Asterisk: through 18.9; 20.7-cert1, 20.7-cert1-rc1, 20.7-cert1-rc2, 20.7-cert2, 20.7-cert3, 20.7-cert4 (+2)
How to fix
Upgrade to a fixed version: asterisk 18.26.3, 20.15.1, 21.10.1, 22.5.1. Check the vendor advisory for mitigations.
References
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