Debian Security Advisory
DSA-2763-1 pyopenssl -- hostname check bypassing
- Date Reported:
- 24 Sep 2013
- Affected Packages:
- Security database references:
- In the Debian bugtracking system: Bug 722055.
In Mitre's CVE dictionary: CVE-2013-4314.
- More information:
It was discovered that PyOpenSSL, a Python wrapper around the OpenSSL library, does not properly handle certificates with NULL characters in the Subject Alternative Name field.
A remote attacker in the position to obtain a certificate for 'www.foo.org\0.example.com' from a CA that a SSL client trusts, could use this to spoof
www.foo.organd conduct man-in-the-middle attacks between the PyOpenSSL-using client and the SSL server.
For the oldstable distribution (squeeze), this problem has been fixed in version 0.10-1+squeeze1.
For the stable distribution (wheezy), this problem has been fixed in version 0.13-2+deb7u1.
For the unstable distribution (sid), this problem has been fixed in version 0.13-2.1.
We recommend that you upgrade your pyopenssl packages.