Description
The is_asn1 function in strongSwan 4.1.11 through 5.0.4 does not properly validate the return value of the asn1_length function, which allows remote attackers to cause a denial of service (segmentation fault) via a (1) XAuth username, (2) EAP identity, or (3) PEM encoded file that starts with a 0x04, 0x30, or 0x31 character followed by an ASN.1 length value that triggers an integer overflow.
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.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | strongswan | 5.3.5-1.1 | openSUSE-SU-2024:10579-1 |
Advisories 1
- openSUSE-SU-2024:10579-1 strongswan-5.3.5-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- 54315 third-party-advisory
- 61564 vdb-entry
- 54524 third-party-advisory
- http://strongswan.org/blog/2013/08/01/strongswan-5.1.0-released.html
- openSUSE-SU-2013:1333 vendor-advisory
- http://strongswan.org/blog/2013/08/01/strongswan-denial-of-service-vulnerability-%28cve-2013-5018%29.html
- openSUSE-SU-2013:1332 vendor-advisory
- [Users] 20130729 [strongSwan] charon crash right after xauth+rsa client connects (strongswan-5.0.4, ubuntu 12.04) mailing-list
- openSUSE-SU-2013:1372 vendor-advisory