CVE-2021-4240

A vulnerability, which was classified as problematic, was found in phpservermon. This affects the function generatePasswordResetToken of the file src/psm/Service/User.php. The manipulation leads to use of predictable algorithm in random number generator. The exploit has been disclosed to the public and may be used. The name of the patch is 3daa804d5f56c55b3ae13bfac368bb84ec632193. It is recommended to apply a patch to fix this issue. The identifier VDB-213717 was assigned to this vulnerability.

Weakness

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected Software

Potential Mitigations

• Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.
• In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.
• Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a “random enough” number.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/112.html
• https://cwe.mitre.org/data/definitions/485.html
• https://cwe.mitre.org/data/definitions/59.html

References

• https://github.com/phpservermon/phpservermon/commit/3daa804d5f56c55b3ae13bfac368bb84ec632193
• https://huntr.dev/bounties/2-phpservermon/phpservermon/
• https://vuldb.com/?id.213717