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Fencer Vulns
low 3.5

CVE-2021-27913 json

Use of a Broken or Risky Cryptographic Algorithm

published 2021-08-30 5 y ago modified 2026-07-08 4 mo ago also GHSA-x7g2-wrrp-r6h3 , EUVD-2021-2132

cvss
3.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

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 This issue affects: Mautic Mautic versions prior to 3.3.4; versions prior to 4.0.0.

Patch / fix

  • packagist mautic/core 3.3.4, 4.0.0
  • Mautic Mautic 3.3.4, 4.0.0

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/mautic/mautic/security/advisories/GHSA-x7g2-wrrp-r6h3 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 3.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
NVD 3.1 3.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:P/I:N/A:N
GitHub 3.1 3.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
packagist mautic/core
<3.3.4
>=4.0.0-alpha1, <4.0.0
3.3.4
4.0.0

Affected products

  • Mautic Mautic

Classification

Weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm
  • CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.