GitHub Advisoryadvisory · Go
GHSA-xg2h-wx96-xgxr RandomAlphaNumeric and CryptoRandomAlphaNumeric are not as random as they should be
LOW
Official page ↗
- Aliases
- CVE-2021-4238
- Ecosystem
- Go
- Packages
- github.com/Masterminds/goutils
- Severity
- Low
- Weaknesses
- CWE-331
- Reviewed
- 2021-05-21
Affected packages
• Go github.com/Masterminds/goutils: < 1.1.1 → fixed in 1.1.1
Description
Impact
A security-sensitive bug was discovered by Open Source Developer *Erik Sundell of Sundell Open Source Consulting AB*.
The functions `RandomAlphaNumeric(int)` and `CryptoRandomAlphaNumeric(int)` are not as random as they should be. Small values of `int` in the functions above will return a smaller subset of results than they should. For example, `RandomAlphaNumeric(1)` will always return a digit in the 0-9 range, while `RandomAlphaNumeric(4)` will return around ~7 million of the ~13M possible permutations.
This is considered a security release because programs that rely upon random generators for passwords are at an increased risk of brute force-style password guessing. There is also a higher probability of collision.
The problem was the result of a mistaken regular expression that only accepted random strings if they contained a digit from `[0-9]`. That restriction has been removed.
Patches
This issue has been corrected in v1.1.1.
Workarounds
If you cannot upgrade to v1.1.1, you can work around the issue by calling `RandomAlphaNumericCustom(N, true, true)`|`CryptoRandomAlphaNumericCustom(N, true, true)` instead. (Where `N` is the desired length, and `true` is the literal boolean `true`.)
Related
Alias · CVE (1)
- CVE-2021-4238 Randomly-generated alphanumeric strings contain significantly less entropy than expected. vulnerability
Weakness · CWE (1)
- CWE-331 Insufficient Entropy weakness
References
- https://github.com/Masterminds/goutils/security/advisories/GHSA-xg2h-wx96-xgxr web
- https://nvd.nist.gov/vuln/detail/CVE-2021-4238 advisory
- https://github.com/Masterminds/goutils/commit/869801f20f9f1e7ecdbdb6422049d8241270d5e1 web
- https://github.com/Masterminds/goutils/commit/f1923532a168b8203bfe956d8cd3b17ebece5982 web
- https://github.com/Masterminds/goutils package
- https://github.com/Masterminds/goutils/releases/tag/v1.1.1 web
- https://pkg.go.dev/vuln/GO-2022-0411 web