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case insensitive password comparison

Project curl Security Advisory, November 2, 2016 - Permalink

VULNERABILITY

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.

We are not aware of any exploit of this flaw.

INFO

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2016-8616 to this issue.

AFFECTED VERSIONS

This flaw exists in the following curl versions.

libcurl is used by many applications, but not always advertised as such!

THE SOLUTION

In version 7.51.0, the comparisons are done case sensitively.

A patch for CVE-2016-8616 is available.

RECOMMENDATIONS

We suggest you take one of the following actions immediately, in order of preference:

A - Upgrade curl and libcurl to version 7.51.0

B - Apply the patch to your version and rebuild

TIME LINE

It was first reported to the curl project on September 23 by Cure53.

We contacted distros@openwall on October 19.

curl 7.51.0 was released on November 2 2016, coordinated with the publication of this advisory.

CREDITS

This vulnerability was found during a Secure Open Source audit performed by Cure53.