curl: TLS/SSL certificate name check disabled with peer verification when using GnuTLS
Published Dec 23, 2013
4.0
MEDIUMCVSS 2.0
EPSS 2.80%
Description
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.
Affected products
No data.
Configuration 1
- 7.0
Configuration 2
- 12.04
- 12.10
- 13.04
- 13.10
Configuration 3
- 7.21.4
- 7.21.5
- 7.21.6
- 7.21.7
- 7.22.0
- 7.23.0
- 7.23.1
- 7.24.0
- 7.25.0
- 7.26.0
- 7.27.0
- 7.28.0
- 7.28.1
- 7.29.0
- 7.30.0
- 7.31.0
- 7.32.0
- 7.33.0
No data.
Red Hat Enterprise Linux 5
curl
Not affected
Red Hat Enterprise Linux 6
curl
Not affected
Red Hat Enterprise Linux 7
curl
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | curl | Not affected | n/a |
| Red Hat Enterprise Linux 6 | curl | Not affected | n/a |
| Red Hat Enterprise Linux 7 | curl | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Not vulnerable. This issue did not affect the versions of curl as shipped with Red Hat Enterprise Linux 5 and 6.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:N/AC:H/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.80% (0.02798) | 85.96th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.76% (0.02761) | 84.30th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.34% (0.00344) | 54.84th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.24% (0.00245) | 65.12th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.24% (0.00245) | 63.63th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.24% (0.00245) | 60.66th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.21% (0.01213) | 66.61th | v2 (v2022.01.01) |
| Feb 17, 2023 | 1.21% (0.01213) | 66.22th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.21% (0.01213) | 64.21th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.21% (0.01213) | 40.54th | v2 (v2022.01.01) |
References (9)
- http://curl.haxx.se/docs/adv_20131217.html x_refsource_CONFIRMVendor Advisory
- http://www.debian.org/security/2013/dsa-2824 vendor-advisoryx_refsource_DEBIAN
- http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html x_refsource_CONFIRM
- http://www.ubuntu.com/usn/USN-2058-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2013-6422 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1037918 Issue Tracking
- https://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c04463322 vendor-advisoryx_refsource_HP
- https://nvd.nist.gov/vuln/detail/CVE-2013-6422
- https://www.cve.org/CVERecord?id=CVE-2013-6422
| Link | Providers | Tags |
|---|---|---|
| http://curl.haxx.se/docs/adv_20131217.html | x_refsource_CONFIRMVendor Advisory | |
| http://www.debian.org/security/2013/dsa-2824 | vendor-advisoryx_refsource_DEBIAN | |
| http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html | x_refsource_CONFIRM | |
| http://www.ubuntu.com/usn/USN-2058-1 | vendor-advisoryx_refsource_UBUNTU | |
| https://access.redhat.com/security/cve/CVE-2013-6422 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1037918 | Issue Tracking | |
| https://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c04463322 | vendor-advisoryx_refsource_HP | |
| https://nvd.nist.gov/vuln/detail/CVE-2013-6422 | ||
| https://www.cve.org/CVERecord?id=CVE-2013-6422 |
Change history (0)
No recorded changes yet.