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[SECURITY ADVISORY] curl: RTSP RTP buffer over-read

From: Daniel Stenberg <>
Date: Wed, 14 Mar 2018 07:55:11 +0100 (CET)

RTSP RTP buffer over-read

Project curl Security Advisory, March 14th 2018 -


curl can be tricked into copying data beyond end of its heap based buffer.

When asked to transfer an RTSP URL, curl could calculate a wrong data length
to copy from the read buffer. The memcpy call would copy data from the heap
following the buffer to a storage area that would subsequently be delivered to
the application (if it didn't cause a crash). We've managed to get it to reach
several hundreds bytes out of range.

This could lead to information leakage or a denial of service for the
application if the server offering the RTSP data can trigger this.

We are not aware of any exploit of this flaw.


This bug was introduced in January 2010 in [this
commit]( when RTSP support
was first added.
The Common Vulnerabilities and Exposures (CVE) project has assigned the name
CVE-2018-1000122 to this issue.
CWE-126: Buffer Over-read
- Affected versions: curl 7.20.0 to and including curl 7.58.0
- Not affected versions: curl < 7.20.0 and curl >= 7.59.0
libcurl is used by many applications, but not always advertised as such.
In curl version 7.59.0, curl makes sure that this code never gets told to copy
more data than it is allowed to read from the buffer.
A [patch for CVE-2018-1000122]( is available.
We suggest you take one of the following actions immediately, in order of
  A - Upgrade curl to version 7.59.0
  B - Apply the patch to your version and rebuild
It was reported to the curl project on February 20, 2018
We contacted distros_at_openwall on March 8, 2018.
curl 7.59.0 was released on March 14 2018, coordinated with the publication of
this advisory.
Detected by OSS-fuzz. Assisted by Max Dymond. Patch by Daniel Stenberg.
Thanks a lot!
Received on 2018-03-14