Ubuntu Security Notice USN-1484-1
28th June, 2012
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 12.04 LTS
- Ubuntu 11.10
- Ubuntu 11.04
- Ubuntu 10.04 LTS
PyCrypto improperly created ElGamal encryption keys.
- python-crypto - cryptographic algorithms and protocols for Python
It was discovered that PyCrypto produced inappropriate prime numbers when
generating ElGamal keys. An attacker could use this flaw to facilitate
brute-forcing of ElGamal encryption keys.
The problem can be corrected by updating your system to the following package version:
- Ubuntu 12.04 LTS:
- python-crypto 2.4.1-1ubuntu0.1
- Ubuntu 11.10:
- python-crypto 2.3-2ubuntu0.1
- Ubuntu 11.04:
- python-crypto 2.1.0-2ubuntu1.1
- Ubuntu 10.04 LTS:
- python-crypto 2.0.1+dfsg1-4ubuntu2.2
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.
If PyCrypto was used to generate ElGamal keys, we recommend they be