GitHub Advisoryadvisory · Packagist
GHSA-x7g2-wrrp-r6h3 Use of a Broken or Risky Cryptographic Algorithm
LOW
Official page ↗
- Aliases
- CVE-2021-27913
- Ecosystem
- Packagist
- Packages
- mautic/core
- Severity
- Low
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
- Weaknesses
- CWE-327
- Reviewed
- 2021-08-30
Affected packages
• Packagist mautic/core: < 3.3.4 → fixed in 3.3.4
• Packagist mautic/core: >= 4.0.0-alpha1, < 4.0.0 → fixed in 4.0.0
Description
✍️ Description
The function mt_rand is used to generate session tokens, this function is cryptographically flawed due to its nature being one pseudorandomness, an attacker can take advantage of the cryptographically insecure nature of this function to enumerate session tokens for accounts that are not under his/her control
🕵️♂️ Proof of Concept
Numerous examples and attack implementations can be found in this paper . If you're looking for a practical tool that can crack your mt_rand implementation's seed value, see this project and run the following commands in a console with php5 and OpenWall's tool installed:
`root$ php -r 'mt_srand(13333337); echo mt_rand( ), "\n";'`
After that, copy the output (1863134308) and execute the following commands:
`root$ gcc php_mt_seed.c -o php_mt_seedroot$ ./php_mt_seed 1863134308`
After waiting ~1 minute you should have a few possible seeds corresponding to their PHP versions, next to your installed PHP version you should see something akin to:
seed = 0x00cb7359 = 13333337 (PHP 7.1.0+)
Hey, that's your seed!
💥 Impact
An attacker could takeover accounts at random by enumerating and using access tokens.
📝 References
• https://openwall.com/php_mt_seedhttps://crypto.di.uoa.gr/CRYPTO.SEC/Randomness_Attacks_files/paper.pdf
• https://github.com/mautic/mautic/blob/5213e320b4ef4d0c51bb84c1d46a1071e8e4f7fc/app/bundles/PointBundle/Controller/TriggerController.php#L187
• https://github.com/mautic/mautic/releases/tag/3.3.4
• https://github.com/mautic/mautic/releases/tag/4.0.0
Related
Alias · CVE (1)
- CVE-2021-27913 The function mt_rand is used to generate session tokens, this function is cryptographically flawed due to its nature being one… vulnerability
Weakness · CWE (1)
- CWE-327 Use of a Broken or Risky Cryptographic Algorithm weakness
References
- https://github.com/mautic/mautic/security/advisories/GHSA-x7g2-wrrp-r6h3 web
- https://nvd.nist.gov/vuln/detail/CVE-2021-27913 advisory
- https://github.com/mautic/mautic/commit/d1cad766a2de74e6c6b89d6d78c2a5f2e36ba91c web
- https://github.com/FriendsOfPHP/security-advisories/blob/master/mautic/core/CVE-2021-27913.yaml web
- https://github.com/mautic/mautic package