An issue was discovered in Enigmail before 1.9.9. Improper Random Secret Generation occurs because Math.Random() is used by pretty Easy privacy (pEp), aka TBE-01-001.
Weakness
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG’s algorithm is not cryptographically strong.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Enigmail | Enigmail | * | 1.9.9 (excluding) |
| Enigmail | Ubuntu | artful | * |
| Enigmail | Ubuntu | esm-apps/xenial | * |
| Enigmail | Ubuntu | trusty | * |
| Enigmail | Ubuntu | upstream | * |
| Enigmail | Ubuntu | xenial | * |
| Enigmail | Ubuntu | zesty | * |
Extended Description
When a non-cryptographic PRNG is used in a cryptographic context, it can expose the cryptography to certain types of attacks. Often a pseudo-random number generator (PRNG) is not designed for cryptography. Sometimes a mediocre source of randomness is sufficient or preferable for algorithms that use random numbers. Weak generators generally take less processing power and/or do not use the precious, finite, entropy sources on a system. While such PRNGs might have very useful features, these same features could be used to break the cryptography.
Potential Mitigations
References
- https://enigmail.net/download/other/Enigmail%20Pentest%20Report%20by%20Cure53%20-%20Excerpt.pdf
- https://lists.debian.org/debian-lts-announce/2017/12/msg00021.html
- https://lists.debian.org/debian-security-announce/2017/msg00333.html
- https://www.debian.org/security/2017/dsa-4070
- https://www.mail-archive.com/enigmail-users%40enigmail.net/msg04280.html
- https://enigmail.net/download/other/Enigmail%20Pentest%20Report%20by%20Cure53%20-%20Excerpt.pdf
- https://lists.debian.org/debian-lts-announce/2017/12/msg00021.html
- https://lists.debian.org/debian-security-announce/2017/msg00333.html
- https://www.debian.org/security/2017/dsa-4070
- https://www.mail-archive.com/enigmail-users%40enigmail.net/msg04280.html