CVE-2021-26906
MEDIUMEPSS 84th pctlDescription
An issue was discovered in res_pjsip_session.c in Digium Asterisk through 13.38.1; 14.x, 15.x, and 16.x through 16.16.0; 17.x through 17.9.1; and 18.x through 18.2.0, and Certified Asterisk through 16.8-cert5. An SDP negotiation vulnerability in PJSIP allows a remote server to potentially crash Asterisk by sending specific SIP responses that cause an SDP negotiation failure.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Elevated risk: more likely to be exploited than 84% of all known CVEs.
References
Related Vulnerabilities
Other CWE-404 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2022-44267 | Medium | 6.5 | 77% | - | Fix |
| CVE-2018-8120 | High | 7.0 | 74% | KEV + Ransom | - |
| CVE-2018-8210 | High | 7.8 | 31% | - | - |
| CVE-2018-8639 | High | 7.8 | 22% | KEV + Ransom | - |
| CVE-2023-3206 | Medium | 5.3 | 19% | - | - |
| CVE-2018-8450 | High | 8.8 | 15% | - | - |
Common questions
How do I fix CVE-2021-26906?
Upgrade asterisk on debian 11 to 1:16.16.1~dfsg-1 or later.
Is CVE-2021-26906 being actively exploited?
Not that we know of. CVE-2021-26906 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 2.5% is the estimated probability that it will be exploited in the next 30 days. That is higher than 84% of all scored CVEs.
How severe is CVE-2021-26906?
CVE-2021-26906 has a CVSS v3 base score of 5.9, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-26906 affect?
Published advisories record a fix for asterisk (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2021-26906
Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.