CVE-2016-8616

Severity: medium (CVSS 5.9 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-08-01 · updated 2026-06-17
Weakness: CWE-592

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

curl: before 7.51.0 — fixed in 7.51.0

How to fix

Upgrade to a fixed version: curl 7.51.0. Check the vendor advisory for mitigations.

References

http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
http://www.securityfocus.com/bid/94094
http://www.securitytracker.com/id/1037192
https://access.redhat.com/errata/RHSA-2018:2486
https://access.redhat.com/errata/RHSA-2018:3558
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8616
https://curl.haxx.se/CVE-2016-8616.patch
https://curl.haxx.se/docs/adv_20161102B.html
https://security.gentoo.org/glsa/201701-47
https://www.tenable.com/security/tns-2016-21
http://www.oracle.com/technetwork/security-advisory/cpuoct2018-4428296.html
http://www.securityfocus.com/bid/94094

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