Description
The asn1_signature function in asn1.c in Cameron Hamilton-Rich axTLS through 2.1.5 has a Buffer Overflow that allows remote attackers to cause a denial of service (memory and CPU consumption) via a crafted certificate in the TLS certificate handshake message, because the result of get_asn1_length() is not checked for a minimum or maximum size.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | axtls | No fix yet | — |
| Ubuntu 20.04 LTS | axtls | No fix yet | — |
References
- http://axtls.sourceforge.net
- https://www.telekom.com/en/corporate-responsibility/data-protection-data-security/security/details/advisories-504842
- 20191128 [Public Disclosure] Two Denial-of-Service vulnerabilities found in axTLS library (CVE-2019-9689 / CVE-2019-10013) mailing-list
- http://packetstormsecurity.com/files/155500/axTLS-2.1.5-Denial-Of-Service.html
- https://www.telekom.com/resource/blob/586416/12097aeb8f9a6bba89a804b94575521a/dl-191121-critical-remote-denial-of-service-vulnerability-i--data.pdf