Description
A flaw was found in curl before version 7.51.0 When re-using a connection, curl was doing case insensitive comparisons of user name and password with the existing connections. This means that if an unused connection with proper credentials exists for a protocol that has connection-scoped credentials, an attacker can cause that connection to be reused if s/he knows the case-insensitive version of the correct password.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| The Curl Project | curl | 7.51.0 | — |
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 | 7.51.0-1 | — |
| Debian 13 | curl | 7.51.0-1 | — |
| Debian 12 | curl | 7.51.0-1 | — |
| Debian 8 | curl | 7.38.0-4+deb8u5 | DSA-3705-1 |
| Debian 7 | curl | 7.26.0-1+wheezy17 | DLA-711-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | curl | 7.47.0-1ubuntu2.2 | USN-3123-1 |
| Ubuntu 14.04 LTS | curl | 7.35.0-1ubuntu2.10 | USN-3123-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 3 | httpd24-curl +2 | 7.61.1-1.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-httpd +5 | 2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_md | 2.4.34-7.el7 | RHSA-2018:3558 |
| RHEL 3 | httpd24-mod_ssl +1 | 1:2.4.34-7.el6 | RHSA-2018:3558 |
| RHEL 3 | httpd24-nghttp2 +2 | 1.7.1-7.el6 | RHSA-2018:3558 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | curl | 7.37.0-31.1 | SUSE-SU-2016:2699-1 |
| SLES 11 SP4 | curl | 7.19.7-1.64.1 | SUSE-SU-2016:2714-1 |
| SLES 11 | curl-openssl1 | 7.19.7-1.64.1 | SUSE-SU-2016:2714-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Studio Onsite 1.3 | curl | 7.19.7-1.20.47.2 | SUSE-SU-2016:2700-1 |
| SLES for SAP 12 SP1 | curl | 7.37.0-31.1 | SUSE-SU-2016:2699-1 |
| SLES for SAP 11 SP4 | curl | 7.19.7-1.64.1 | SUSE-SU-2016:2714-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | curl | 7.51.0-1.1 | openSUSE-SU-2024:10303-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | curl | 7.51.0-r0 | — |
| Alpine v3.23 | curl | 7.51.0-r0 | — |
| Alpine v3.22 | curl | 7.51.0-r0 | — |
| Alpine v3.21 | curl | 7.51.0-r0 | — |
| Alpine v3.20 | curl | 7.51.0-r0 | — |
Show 18 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | curl | 7.51.0-r0 | — |
| Alpine v3.18 | curl | 7.51.0-r0 | — |
| Alpine v3.17 | curl | 7.51.0-r0 | — |
| Alpine v3.16 | curl | 7.51.0-r0 | — |
| Alpine v3.15 | curl | 7.51.0-r0 | — |
| Alpine v3.14 | curl | 7.51.0-r0 | — |
| Alpine v3.13 | curl | 7.51.0-r0 | — |
| Alpine v3.12 | curl | 7.51.0-r0 | — |
| Alpine v3.11 | curl | 7.51.0 | — |
| Alpine v3.10 | curl | 7.51.0-r0 | — |
| Alpine v3.9 | curl | 7.51.0-r0 | — |
| Alpine v3.8 | curl | 7.51.0 | — |
| Alpine v3.7 | curl | 7.51.0 | — |
| Alpine v3.6 | curl | 7.51.0 | — |
| Alpine v3.5 | curl | 7.51.0-r0 | — |
| Alpine v3.4 | curl | 7.51.0-r0 | — |
| Alpine v3.3 | curl | 7.49.1-r4 | — |
| Alpine v3.2 | curl | 7.49.1-r4 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | curl +2 | 7.29.0-51.0.1.el7 | ELSA-2019-4652 |
Advisories 11
- RHSA-2018:3558 Red Hat Security Advisory: httpd24 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 21, 2026
- USN-3123-1 curl vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-711-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3705-1 curl - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2016:2699-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2016:2700-1 Security update for curl SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10303-1 curl-7.51.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2026-0180 Dell Data Protection Advisor: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 20, 2026
- SUSE-SU-2016:2714-1 Security update for curl SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2023-1652 cURL: Mehrere Schwachstellen BSI CERT-Bund (WID) · Dec 13, 2023
- ELSA-2019-4652 Important: curl security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 21, 2019
References
- 94094 vdb-entry
- RHSA-2018:3558 vendor-advisory
- https://curl.haxx.se/docs/adv_20161102B.html
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8616
- https://curl.haxx.se/CVE-2016-8616.patch
- https://www.tenable.com/security/tns-2016-21
- 1037192 vdb-entry
- http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
- RHSA-2018:2486 vendor-advisory
- GLSA-201701-47 vendor-advisory