The GnuTLS backend in libcurl 7.21.4 through 7.33.0, when disabling digital signature verification (CURLOPT_SSL_VERIFYPEER), also disables the CURLOPT_SSL_VERIFYHOST check for CN or SAN host name fields, which makes it easier for remote attackers to spoof servers and conduct man-in-the-middle (MITM) attacks.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2013-6422 from the MITRE CVE dictionary dictionary and NIST NVD.
Not vulnerable. This issue did not affect the versions of curl as shipped with Red Hat Enterprise Linux 5 and 6.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 2.6 |
|---|---|
| Base Metrics | AV:N/AC:H/Au:N/C:N/I:P/A:N |
| Access Vector | Network |
| Access Complexity | High |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | Partial |
| Availability Impact | None |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 7 | curl | Not affected |
| Red Hat Enterprise Linux 6 | curl | Not affected |
| Red Hat Enterprise Linux 5 | curl | Not affected |
Vulmon