The Crypto.Random.atfork function in PyCrypto before 2.6.1 does not properly reseed the pseudo-random number generator (PRNG) before allowing a child process to access it, which makes it easier for context-dependent attackers to obtain sensitive information by leveraging a race condition in which a child process is created and accesses the PRNG within the same rate-limit period as another process.

References

• https://nvd.nist.gov/vuln/detail/CVE-2013-1445
• pycrypto/pycrypto@19dcf7b
• http://www.debian.org/security/2013/dsa-2781
• http://www.openwall.com/lists/oss-security/2013/10/17/3