Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [day] [month] [year] [list]
Date: Wed, 6 Feb 2019 08:12:29 +0100 (CET)
From: Daniel Stenberg <daniel@...x.se>
To: curl security announcements -- curl users <curl-users@...l.haxx.se>,
        curl-announce@...l.haxx.se,
        libcurl hacking <curl-library@...l.haxx.se>,
        oss-security@...ts.openwall.com
Subject: [SECURITY ADVISORY] curl: NTLM type-2 out-of-bounds buffer read

NTLM type-2 out-of-bounds buffer read
=====================================

Project curl Security Advisory, February 6th 2019 -
[Permalink](https://curl.haxx.se/docs/CVE-2018-16890.html)

VULNERABILITY
-------------

libcurl contains a heap buffer out-of-bounds read flaw.

The function handling incoming NTLM type-2 messages
(`lib/vauth/ntlm.c:ntlm_decode_type2_target`) does not validate incoming data
correctly and is subject to an integer overflow vulnerability.

Using that overflow, a malicious or broken NTLM server could trick libcurl to
accept a bad length + offset combination that would lead to a buffer read
out-of-bounds.

We are not aware of any exploit of this flaw.

INFO
----

This bug was introduced in [commit
86724581b6c](https://github.com/curl/curl/commit/86724581b6c), January 2014.

The Common Vulnerabilities and Exposures (CVE) project has assigned the name
CVE-2018-16890 to this issue.

CWE-125: Out-of-bounds Read

Severity: 5.3 (Medium)

AFFECTED VERSIONS
-----------------

- Affected versions: libcurl 7.36.0 to and including 7.63.0
- Not affected versions: libcurl < 7.36.0 and >= 7.64.0

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

THE SOLUTION
------------

A [patch for CVE-2018-16890](https://github.com/curl/curl/commit/b780b30d1377adb10bbe774835f49e9b237fb9bb)

RECOMMENDATIONS
---------------

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

  A - Upgrade curl to version 7.64.0

  B - Apply the patch to your version and rebuild

  C - Turn off NTLM authentication

TIME LINE
---------

It was reported to the curl project on December 30, 2018. We contacted
distros@...nwall on January 28.

curl 7.64.0 was released on February 6 2019, coordinated with the publication
of this advisory.

CREDITS
-------

Reported by Wenxiang Qian of Tencent Blade Team. Patch by Daniel Stenberg.

Thanks a lot!

-- 

  / daniel.haxx.se

Powered by blists - more mailing lists

Your e-mail address:

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.