How severe is CVE-2021-22948?

CVE-2021-22948 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2021-22948 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22948?

CVE-2021-22948 primarily affects Revive-adserver Revive Adserver. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22948?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-22948 published?

CVE-2021-22948 was published on 2021-09-23 and last updated on 2026-06-17.

CVE-2021-22948

CVE-2021-22948 is a high-severity vulnerability in Revive-adserver Revive Adserver with a CVSS 3.x base score of 7.1. 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: High (CVSS 3.x base score 7.1)
CVSS v2: 4.3
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-338
Affected product: Revive-adserver Revive Adserver
Published: 2021-09-23
Last modified: 2026-06-17

Description

Vulnerability in the generation of session IDs in revive-adserver < 5.3.0, based on the cryptographically insecure uniqid() PHP function. Under some circumstances, an attacker could theoretically be able to brute force session IDs in order to take over a specific account.

Frequently asked questions

What is CVE-2021-22948?: Vulnerability in the generation of session IDs in revive-adserver < 5.3.0, based on the cryptographically insecure uniqid() PHP function. Under some circumstances, an attacker could theoretically be able to brute force session IDs in order to take over a specific account.
How severe is CVE-2021-22948?: CVE-2021-22948 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2021-22948 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22948?: CVE-2021-22948 primarily affects Revive-adserver Revive Adserver. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22948?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-22948 published?: CVE-2021-22948 was published on 2021-09-23 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:revive-adserver:revive_adserver:*:*:*:*:*:*:*:*
cpe:2.3:a:revive-adserver:revive_adserver:5.3.0:rc1:*:*:*:*:*:*

More vulnerabilities in Revive-adserver Revive Adserver

CVE-2016-9125 — Critical (CVSS 9.8): Revive Adserver before 3.2.3 suffers from session fixation, by allowing arbitrary session identifiers to be forced and,…
CVE-2016-9124 — Critical (CVSS 9.8): Revive Adserver before 3.2.3 suffers from Improper Restriction of Excessive Authentication Attempts. The login page of…
CVE-2017-5830 — Critical (CVSS 9.8): Revive Adserver before 4.0.1 allows remote attackers to execute arbitrary code via serialized data in the cookies…
CVE-2016-9470 — Critical (CVSS 9.0): Revive Adserver before 3.2.5 and 4.0.0 suffers from Reflected File Download. `www/delivery/asyncspc.php` was vulnerable…
CVE-2026-50741 — High (CVSS 8.8): Bypass to the fix for CVE-2026-34916. Variants of such vectors have been also reported by phucrio and offsetmd. The fix…
CVE-2025-48986 — High (CVSS 8.8): Authorization bypass in Revive Adserver 5.5.2 and 6.0.1 and earlier versions causes an logged in attacker to change…

All CVEs affecting Revive-adserver Revive Adserver →

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 →