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Use of a Broken or Risky Cryptographic Algorithm

Low severity GitHub Reviewed Published Aug 30, 2021 in mautic/mautic • Updated Feb 5, 2024

Package

composer mautic/core (Composer)

Affected versions

< 3.3.4
>= 4.0.0-alpha1, < 4.0.0

Patched versions

3.3.4
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

References

@RCheesley RCheesley published to mautic/mautic Aug 30, 2021
Published by the National Vulnerability Database Aug 30, 2021
Reviewed Aug 30, 2021
Published to the GitHub Advisory Database Sep 1, 2021
Last updated Feb 5, 2024

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L

EPSS score

0.058%
(26th percentile)

Weaknesses

CVE ID

CVE-2021-27913

GHSA ID

GHSA-x7g2-wrrp-r6h3

Source code

Credits

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