CVE-2024-1019

WAF bypass of the ModSecurity v3 release line

Published Jan 30, 2024 CVSS 3.1 · 8.6 High EPSS < 1% KEV · Not listed
Description
ModSecurity / libModSecurity 3.0.0 to 3.0.11 is affected by a WAF bypass for path-based payloads submitted via specially crafted request URLs. ModSecurity v3 decodes percent-encoded characters present in request URLs before it separates the URL path component from the optional query string component. This results in an impedance mismatch versus RFC compliant back-end applications. The vulnerability hides an attack payload in the path component of the URL from WAF rules inspecting it. A back-end may be vulnerable if it uses the path component of request URLs to construct queries. Integrators and users are advised to upgrade to 3.0.12. The ModSecurity v2 release line is not affected by this vulnerability.

Remediation

Vendor Solution

Upgrade to ModSecurity 3.0.12.


Vendor Workaround

ModSecurity v3’s REQUEST_URI_RAW variable contains the full URI and is unaffected by the URL decoding step. It is therefore possible to use the REQUEST_URI_RAW variable to derive all other required variables correctly, including performing any required URL decoding.

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2024-16796 ModSecurity / libModSecurity 3.0.0 to 3.0.11 is affected by a WAF bypass for path-based payloads submitted via specially crafted request URLs. ModSecurity v3 decodes percent-encoded characters present in request URLs before it separates the URL path component from the optional query string component. This results in an impedance mismatch versus RFC compliant back-end applications. The vulnerability hides an attack payload in the path component of the URL from WAF rules inspecting it. A back-end may be vulnerable if it uses the path component of request URLs to construct queries. Integrators and users are advised to upgrade to 3.0.12. The ModSecurity v2 release line is not affected by this vulnerability.
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Owasp
Owasp modsecurity
CPEs cpe:2.3:a:trustwave:modsecurity:*:*:*:*:*:*:*:* cpe:2.3:a:owasp:modsecurity:*:*:*:*:*:*:*:*
Vendors & Products Trustwave
Trustwave modsecurity
Owasp
Owasp modsecurity
Type Values Removed Values Added
Description ModSecurity / libModSecurity 3.0.0 to 3.0.11 is affected by a WAF bypass for path-based payloads submitted via specially crafted request URLs. ModSecurity v3 decodes percent-encoded characters present in request URLs before it separates the URL path component from the optional query string component. This results in an impedance mismatch versus RFC compliant back-end applications. The vulnerability hides an attack payload in the path component of the URL from WAF rules inspecting it. A back-end may be vulnerable if it uses the path component of request URLs to construct queries. Integrators and users are advised to upgrade to 3.0.12. The ModSecurity v2 release line is not affected by this vulnerability. ModSecurity / libModSecurity 3.0.0 to 3.0.11 is affected by a WAF bypass for path-based payloads submitted via specially crafted request URLs. ModSecurity v3 decodes percent-encoded characters present in request URLs before it separates the URL path component from the optional query string component. This results in an impedance mismatch versus RFC compliant back-end applications. The vulnerability hides an attack payload in the path component of the URL from WAF rules inspecting it. A back-end may be vulnerable if it uses the path component of request URLs to construct queries. Integrators and users are advised to upgrade to 3.0.12. The ModSecurity v2 release line is not affected by this vulnerability.
Weaknesses

Sources

Status
PUBLISHED
Assigner
NCSC.ch
Published
Updated
Jun 17, 2025, 9:29 PM
Reserved
Jan 29, 2024, 10:28 AM
Status
Modified
Published
Jan 30, 2024, 4:15 PM
Modified
Jun 17, 2026, 7:03 AM