Arch Linux

Please read this before reporting a bug:

Do NOT report bugs when a package is just outdated, or it is in the AUR. Use the 'flag out of date' link on the package page, or the Mailing List.

REPEAT: Do NOT report bugs for outdated packages!

FS#53742 - [curl] CVE-2017-7468 - TLS session resumption occurs when client certificate changed

Attached to Project: Arch Linux
Opened by Alif (alive4ever) - Friday, 21 April 2017, 15:24 GMT
Last edited by Doug Newgard (Scimmia) - Sunday, 30 April 2017, 17:13 GMT
Task Type Bug Report
Category Packages: Core
Status Closed
Assigned To Dave Reisner (falconindy)
Levente Polyak (anthraxx)
Architecture All
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


According to upstream explanation[1]
libcurl would attempt to resume a TLS session even if the client certificate had changed. That is unacceptable since a server by specification is allowed to skip the client certificate check on resume, and may instead use the old identity which was established by the previous certificate (or no certificate).

libcurl supports by default the use of TLS session id/ticket to resume previous TLS sessions to speed up subsequent TLS handshakes. They are used when for any reason an existing TLS connection couldn't be kept alive to make the next handshake faster.

This flaw is a regression and identical to CVE-2016-5419 reported on August 3rd 2016, but affecting a different version range.

We are not aware of any exploit of this flaw.

Additional info:
* package version(s): 7.53.1-1
* config and/or log files etc.

Steps to reproduce:
$ curl --version
curl 7.53.1

From the upstream security advisory page:
This flaw is relevant for all versions of curl and libcurl that support TLS and client certificates.

Affected versions: curl 7.52.0 to and including 7.53.1
Not affected versions: curl < 7.52.0 and >= 7.54.0

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

This task depends upon

Closed by  Doug Newgard (Scimmia)
Sunday, 30 April 2017, 17:13 GMT
Reason for closing:  Fixed
Additional comments about closing:  7.54.0-1