Description
cURL and libcurl 7.18.0 through 7.32.0, when built with OpenSSL, disables the certificate CN and SAN name field verification (CURLOPT_SSL_VERIFYHOST) when the digital signature verification (CURLOPT_SSL_VERIFYPEER) is disabled, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | curl | 7.33.0-1 | — |
| Debian 13 | curl | 7.33.0-1 | — |
| Debian 12 | curl | 7.33.0-1 | — |
| Debian 7 | curl | 7.26.0-1+wheezy5 | DSA-2798-1 |
| Debian 6.0 | curl | 7.21.0-2.1+squeeze5 | DSA-2798-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | curl | 7.51.0-1.1 | openSUSE-SU-2024:10303-1 |
Advisories 3
- DSA-2798-1 curl - unchecked ssl certificate host name Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10303-1 curl-7.51.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-1656 cURL: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen BSI CERT-Bund (WID) · Jul 4, 2023
References
- http://www.oracle.com/technetwork/topics/security/cpujul2015-2367936.html
- HPSBMU03112 vendor-advisory
- http://curl.haxx.se/docs/adv_20131115.html
- http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.html
- http://www.oracle.com/technetwork/topics/security/cpuapr2015-2365600.html
- DSA-2798 vendor-advisory
- openSUSE-SU-2013:1859 vendor-advisory
- USN-2048-1 vendor-advisory
- openSUSE-SU-2013:1865 vendor-advisory