USN-1158-1: curl vulnerabilities

24 June 2011

curl vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 11.04
  • Ubuntu 10.10
  • Ubuntu 10.04 LTS
  • Ubuntu 8.04 LTS


Multiple vulnerabilities in curl.

Software Description

  • curl - HTTP, HTTPS, and FTP client and client libraries


Richard Silverman discovered that when doing GSSAPI authentication, libcurl unconditionally performs credential delegation, handing the server a copy of the client’s security credential. (CVE-2011-2192)

Wesley Miaw discovered that when zlib is enabled, libcurl does not properly restrict the amount of callback data sent to an application that requests automatic decompression. This might allow an attacker to cause a denial of service via an application crash or possibly execute arbitrary code with the privilege of the application. This issue only affected Ubuntu 8.04 LTS and Ubuntu 10.04 LTS. (CVE-2010-0734)

USN 818-1 fixed an issue with curl’s handling of SSL certificates with zero bytes in the Common Name. Due to a packaging error, the fix for this issue was not being applied during the build. This issue only affected Ubuntu 8.04 LTS. We apologize for the error. (CVE-2009-2417)

Original advisory details:

Scott Cantor discovered that curl did not correctly handle SSL certificates with zero bytes in the Common Name. A remote attacker could exploit this to perform a man in the middle attack to view sensitive information or alter encrypted communications.

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 11.04
libcurl3 - 7.21.3-1ubuntu1.2
libcurl3-gnutls - 7.21.3-1ubuntu1.2
libcurl3-nss - 7.21.3-1ubuntu1.2
Ubuntu 10.10
libcurl3 - 7.21.0-1ubuntu1.1
libcurl3-gnutls - 7.21.0-1ubuntu1.1
Ubuntu 10.04 LTS
libcurl3 - 7.19.7-1ubuntu1.1
libcurl3-gnutls - 7.19.7-1ubuntu1.1
Ubuntu 8.04 LTS
libcurl3 - 7.18.0-1ubuntu2.3
libcurl3-gnutls - 7.18.0-1ubuntu2.3

To update your system, please follow these instructions:

After a standard system update you need to restart any applications that make use of libcurl to make all the necessary changes.