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.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2013-5018 from the MITRE CVE dictionary dictionary and NIST NVD.
Not vulnerable. This issue did not affect the versions of openswan as shipped with Red Hat Enterprise Linux 5 or 6 as they did not include the problematic newline checks when validating ASN.1 length.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 4.3 |
|---|---|
| Base Metrics | AV:N/AC:M/Au:N/C:N/I:N/A:P |
| Access Vector | Network |
| Access Complexity | Medium |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | Partial |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 7 | openswan | Not affected |
| Red Hat Enterprise Linux 6 | openswan | Not affected |
| Red Hat Enterprise Linux 5 | openswan | Not affected |
Vulmon