CVE-2021-26717
First published: Thu Feb 18 2021(Updated: )
An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.
Credit: cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Digium Asterisk | >=16.0.0<16.16.1 | |
| Digium Asterisk | >=17.0.0<17.9.2 | |
| Digium Asterisk | >=18.0<18.2.1 | |
| Digium Certified Asterisk | =16.8 | |
| Digium Certified Asterisk | =16.8-cert1-rc1 | |
| Digium Certified Asterisk | =16.8-cert1-rc2 | |
| Digium Certified Asterisk | =16.8-cert1-rc3 | |
| Digium Certified Asterisk | =16.8-cert1-rc4 | |
| Digium Certified Asterisk | =16.8-cert2 | |
| Digium Certified Asterisk | =16.8-cert3 | |
| Digium Certified Asterisk | =16.8-cert4 | |
| Digium Certified Asterisk | =16.8-cert4-rc1 | |
| Digium Certified Asterisk | =16.8-cert4-rc2 | |
| Digium Certified Asterisk | =16.8-cert4-rc3 | |
| Digium Certified Asterisk | =16.8-cert4-rc4 | |
| Digium Certified Asterisk | =16.8-cert5 |
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Reference Links
- http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.html
- http://seclists.org/fulldisclosure/2021/Feb/58
- https://downloads.asterisk.org/pub/security/
- https://downloads.asterisk.org/pub/security/AST-2021-002.html
- https://issues.asterisk.org/jira/browse/ASTERISK-29203
Frequently Asked Questions
What is the severity of CVE-2021-26717?
The severity of CVE-2021-26717 is high with a severity value of 7.5.
How does CVE-2021-26717 affect Sangoma Asterisk?
CVE-2021-26717 affects Sangoma Asterisk versions 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1, as well as Certified Asterisk versions before 16.8-cert6.
What is the impact of CVE-2021-26717?
The impact of CVE-2021-26717 is that when re-negotiating for T.38, if the initial remote response is delayed just enough, Asterisk may send both audio and T.38 in the SDP.
How do I check if my Sangoma Asterisk installation is affected by CVE-2021-26717?
To check if your Sangoma Asterisk installation is affected, verify the version number and compare it to the affected versions mentioned in the advisory.
How can I mitigate the vulnerability identified in CVE-2021-26717?
To mitigate the vulnerability, upgrade your Sangoma Asterisk installation to version 16.16.1, 17.9.2, 18.2.1, or a later version.
- collector/nvd-index
- agent/severity
- agent/references
- agent/author
- agent/type
- agent/event
- agent/description
- agent/first-publish-date
- agent/softwarecombine
- agent/last-modified-date
- agent/remedy
- agent/tags
- collector/mitre-cve
- source/MITRE
- vendor/digium
- canonical/digium asterisk
- version/digium asterisk/16.0.0
- version/digium asterisk/17.0.0
- version/digium asterisk/18.0
- canonical/digium certified asterisk
- version/digium certified asterisk/16.8
- version/digium certified asterisk/16.8-cert1-rc1
- version/digium certified asterisk/16.8-cert1-rc2
- version/digium certified asterisk/16.8-cert1-rc3
- version/digium certified asterisk/16.8-cert1-rc4
- version/digium certified asterisk/16.8-cert2
- version/digium certified asterisk/16.8-cert3
- version/digium certified asterisk/16.8-cert4
- version/digium certified asterisk/16.8-cert4-rc1
- version/digium certified asterisk/16.8-cert4-rc2
- version/digium certified asterisk/16.8-cert4-rc3
- version/digium certified asterisk/16.8-cert4-rc4
- version/digium certified asterisk/16.8-cert5