#VU42619 Buffer overflow in strongSwan and Opensuse - CVE-2013-5018

Vulnerability identifier: #VU42619

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2013-5018

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
strongSwan
Server applications / Encryption software
Opensuse
Operating systems & Components / Operating system

Vendor: strongswan.org
SUSE

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

strongSwan: 4.1.11 - 5.0.4

Opensuse: 4.1.11 - 12.3

---

External links
https://lists.opensuse.org/opensuse-updates/2013-08/msg00021.html
https://lists.opensuse.org/opensuse-updates/2013-08/msg00022.html
https://lists.opensuse.org/opensuse-updates/2013-08/msg00050.html
https://secunia.com/advisories/54315
https://secunia.com/advisories/54524
https://strongswan.org/blog/2013/08/01/strongswan-5.1.0-released.html
https://strongswan.org/blog/2013/08/01/strongswan-denial-of-service-vulnerability-%28cve-2013-5018%29.html
https://www.securityfocus.com/bid/61564
https://lists.strongswan.org/pipermail/users/2013-July/009540.html

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.