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[SECURITY ADVISORY] curl: URL globbing out of bounds read

From: Daniel Stenberg <daniel_at_haxx.se>
Date: Wed, 9 Aug 2017 08:05:41 +0200 (CEST)

URL globbing out of bounds read
===============================

Project curl Security Advisory, August 9th 2017 -
[Permalink](https://curl.haxx.se/docs/adv_20170809A.html)

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

curl supports "globbing" of URLs, in which a user can pass a numerical range
to have the tool iterate over those numbers to do a sequence of transfers.

In the globbing function that parses the numerical range, there was an
omission that made curl read a byte beyond the end of the URL if given a
carefully crafted, or just wrongly written, URL. The URL is stored in a heap
based buffer, so it could then be made to wrongly read something else instead
of crashing.

An example of a URL that triggers the flaw would be
`http://ur%20[0-60000000000000000000`.

We are not aware of any exploit of this flaw.

INFO

----
This flaw only affects the curl command line tool, not the libcurl
library. The bug was introduced in commit
[5ca96cb84410270](https://github.com/curl/curl/commit/5ca96cb84410270), August
2013. curl 7.34.0.
For version 7.55.0, the parser properly stops at the end of the string and a
test has been added to verify this.
The Common Vulnerabilities and Exposures (CVE) project has assigned the name
CVE-2017-1000101 to this issue.
AFFECTED VERSIONS
-----------------
- Affected versions: curl 7.34.0 to and including 7.54.1
- Not affected versions: curl < 7.34.0 and >= 7.55.1
curl is used by many applications, but not always advertised as such.
THE SOLUTION
------------
A [patch for CVE-2017-1000101](https://curl.haxx.se/CVE-2017-1000101.patch) is
available.
RECOMMENDATIONS
---------------
We suggest you take one of the following actions immediately, in order of
preference:
  A - Upgrade curl to version 7.55.0
  B - Apply the patch to your version and rebuild
TIME LINE
---------
It was reported to the curl project on June 14, 2017.  We contacted
distros_at_openwall on August 1.
curl 7.55.0 was released on August 9 2017, coordinated with the publication of
this advisory.
CREDITS
-------
Reported by Brian Carpenter and Yongji Ouyang (independently of each
other). Patch by Daniel Stenberg.
Thanks a lot!
-- 
  / daniel.haxx.se
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Received on 2017-08-09