How severe is CVE-2021-27913?

CVE-2021-27913 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2021-27913 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27913?

CVE-2021-27913 primarily affects Acquia Mautic. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27913?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-27913 published?

CVE-2021-27913 was published on 2021-08-30 and last updated on 2026-06-17.

CVE-2021-27913

CVE-2021-27913 is a low-severity vulnerability in Acquia Mautic with a CVSS 3.x base score of 3.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-338.

Key facts

Severity: Low (CVSS 3.x base score 3.5)
CVSS v2: 3.5
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-338
Affected product: Acquia Mautic
Published: 2021-08-30
Last modified: 2026-06-17

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

Frequently asked questions

What is CVE-2021-27913?: 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.
How severe is CVE-2021-27913?: CVE-2021-27913 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2021-27913 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27913?: CVE-2021-27913 primarily affects Acquia Mautic. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27913?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27913 published?: CVE-2021-27913 was published on 2021-08-30 and last updated on 2026-06-17.

References

https://github.com/mautic/mautic/security/advisories/GHSA-x7g2-wrrp-r6h3

Affected products (4)

cpe:2.3:a:acquia:mautic:*:*:*:*:*:*:*:*
cpe:2.3:a:acquia:mautic:4.0.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:acquia:mautic:4.0.0:beta:*:*:*:*:*:*
cpe:2.3:a:acquia:mautic:4.0.0:rc:*:*:*:*:*:*

More vulnerabilities in Acquia Mautic

CVE-2022-25772 — Critical (CVSS 9.6): A cross-site scripting (XSS) vulnerability in the web tracking component of Mautic before 4.3.0 allows remote attackers…
CVE-2020-35125 — Critical (CVSS 9.6): A cross-site scripting (XSS) vulnerability in the forms component of Mautic before 3.2.4 allows remote attackers to…
CVE-2020-35124 — Critical (CVSS 9.6): A cross-site scripting (XSS) vulnerability in the assets component of Mautic before 3.2.4 allows remote attackers to…
CVE-2024-47051 — Critical (CVSS 9.1): This advisory addresses two critical security vulnerabilities present in Mautic versions before 5.2.3. These…
CVE-2020-35128 — Critical (CVSS 9.0): Mautic before 3.2.4 is affected by stored XSS. An attacker with permission to manage companies, an application feature,…
CVE-2017-8874 — High (CVSS 8.8): Multiple cross-site request forgery (CSRF) vulnerabilities in Mautic 1.4.1 allow remote attackers to hijack the…

All CVEs affecting Acquia Mautic →

Other CWE-338 vulnerabilities

CVE-2026-56141 — Critical (CVSS 9.8): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429 account…
CVE-2026-3256 — Critical (CVSS 9.8): HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults…
CVE-2025-15604 — Critical (CVSS 9.8): Amon2 versions before 6.17 for Perl use an insecure random_string implementation for security functions. In versions…
CVE-2025-40926 — Critical (CVSS 9.8): Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely. The default session…
CVE-2026-2439 — Critical (CVSS 9.8): Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id…
CVE-2025-15578 — Critical (CVSS 9.8): Maypole versions from 2.10 through 2.13 for Perl generates session ids insecurely. The session id is seeded with the…

Browse all CWE-338 vulnerabilities →