Uncontrolled resource consumption in OpenIDC mod_auth_openidc
Priority LOW 39CWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-400.
Summary
mod_auth_openidc 2.4.0 to 2.4.7 allows a remote attacker to cause a denial-of-service (DoS) condition via unspecified vectors.
Why it matters now
EPSS 0.03395 88th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| OpenIDC | mod_auth_openidc | 2.4.0 to 2.4.7 | — | No fix listed | CNA |
- mod_auth_openidc VendorOpenIDC Affected 2.4.0 to 2.4.7 Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openidc:mod_auth_openidc:*:*:*:*:*:*:*:* | 2.4.0 – 2.4.7 | Vulnerable | OpenIDC |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
| cpe:2.3:a:oracle:essbase:*:*:*:*:*:*:*:* | before 21.3 | Vulnerable | Oracle |
- cpe:2.3:a:openidc:mod_auth_openidc:*:*:*:*:*:*:*:* Versions 2.4.0 – 2.4.7 Vulnerable ·OpenIDC
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
- cpe:2.3:a:oracle:essbase:*:*:*:*:*:*:*:* Versions before 21.3 Vulnerable ·Oracle
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20718
References
More OpenIDC Mod Auth Openidc vulnerabilities
- TI-2024-16331 Denial of service when manipulating mod_auth_openidc_session_chunks cookie in mod_auth_openidc CVSS 3.1HIGH 7.5
- TI-2017-04220 The "OpenID Connect Relying Party and OAuth 2.0 Resource Server" (aka mod_auth_openidc)… CVSS 3.0HIGH 8.6
- TI-2017-03971 The "OpenID Connect Relying Party and OAuth 2.0 Resource Server" (aka mod_auth_openidc)… CVSS 3.0HIGH 8.6
- TI-2023-13144 mod_auth_openidc core dump when OIDCStripCookies is set and an empty Cookie header is supplied CVSS 3.1HIGH 7.5
- TI-2017-03968 Mod_auth_openidc.c in the Ping Identity OpenID Connect authentication module for Apache… CVSS 3.1HIGH 7.5
- TI-2021-12451 Format string bug in the Redis cache implementation CVSS 3.1HIGH 7.5
Sources
- CVE-2021-20718 · CVE Program
- CVE-2021-20718 · NVD
- FIRST EPSS
- CVE-2021-20718 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences