Use after free in Apache HTTP Server
Priority MEDIUM 42CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Partial Red Hat: 4 fixed, 2 without a fix
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
A vulnerability was found in Apache HTTP Server 2.4.17 to 2.4.38. Using fuzzed network input, the http/2 request handling could be made to access freed memory in string comparison when determining the method of a request and thus process the request incorrectly.
Why it matters now
EPSS 0.193 97th percentileScored 2026-11-07
Fix Partial Red Hat: 6 advisoriesRed Hat: 4 fixed, 2 without a fix
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 |
|---|---|---|---|---|---|
| Apache | Apache HTTP Server | 2.4.17 to 2.4.38 | — | No fix listed | CNA |
- Apache HTTP Server VendorApache Affected 2.4.17 to 2.4.38 Fixed in — No fix listed CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* | 2.4.17 – 2.4.38 | Vulnerable | Apache |
| cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* | 14.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* | 18.10 | Vulnerable | Canonical |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
- cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:* Versions 2.4.17 – 2.4.38 Vulnerable ·Apache
- cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:* Versions 14.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:* Versions 18.10 Vulnerable ·Canonical
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
Remediation
Red Hat 6 advisories
- RHSA-2020:4751 Released 2020-11-04 · Red Hat rating Moderatehttpd:2.4 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) httpd-2.4.37-30.module+el8.3.0+7001+0766b9e7.aarch64::httpd:2.4, httpd-2.4.37-30.module+el8.3.0+7001+0766b9e7.ppc64le::httpd:2.4, httpd-2.4.37-30.module+el8.3.0+7001+0766b9e7.s390x::httpd:2.4 +38
- RHSA-2020:2646 Released 2020-06-22 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.37 SP3 security update
- Red Hat JBoss Core Services
- RHSA-2020:2644 Released 2020-06-22 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.37 SP3 security update
- Red Hat JBoss Core Services on RHEL 6 Server jbcs-httpd24-curl-7.64.1-36.jbcs.el6, jbcs-httpd24-httpd-2.4.37-57.jbcs.el6, jbcs-httpd24-httpd-devel-2.4.37-57.jbcs.el6 +18
- Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-curl-7.64.1-36.jbcs.el7, jbcs-httpd24-httpd-2.4.37-57.jbcs.el7, jbcs-httpd24-httpd-devel-2.4.37-57.jbcs.el7 +19
Show 3 more Red Hat advisories
- RHSA-2019:3932 Released 2019-11-20 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.37 Security Release on RHEL 6
- Red Hat JBoss Core Services on RHEL 6 Server jbcs-httpd24-apr-1.6.3-63.jbcs.el6, jbcs-httpd24-apr-devel-1.6.3-63.jbcs.el6, jbcs-httpd24-apr-util-1.6.1-48.jbcs.el6 +37
- RHSA-2019:3933 Released 2019-11-20 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.37 Security Release on RHEL 7
- Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24-apr-1.6.3-63.jbcs.el7, jbcs-httpd24-apr-devel-1.6.3-63.jbcs.el7, jbcs-httpd24-apr-util-1.6.1-48.jbcs.el7 +37
- RHSA-2019:3935 Released 2019-11-20 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.37 Security Release
- Red Hat JBoss Core Services
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat JBoss Enterprise Web Server 2 | Affected | No fix planned: Out of support scope |
| Red Hat Software Collections | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2020:4751 |
| Red Hat JBoss Core Services | Fixed | RHSA-2019:3935 |
| Red Hat JBoss Core Services on RHEL 6 Server | Fixed | RHSA-2019:3932, RHSA-2020:2644 |
| Red Hat JBoss Core Services on RHEL 7 Server | Fixed | RHSA-2019:3933, RHSA-2020:2644 |
Not affected: 4 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Virtualization 4
Timeline
- 2026-10-02 Threatist record created from CVE-2019-0196
- 2026-10-03 Alias added: GHSA-vqc7-p7p7-97wf
References
Advisory 13
- https://httpd.apache.org/security/vulnerabilities_24.html
- [oss-security] 20190401 CVE-2019-0196: mod_http2, read-after-free on a string compare
- 20190403 [SECURITY] [DSA 4422-1] apache2 security update
- USN-3937-1
- FEDORA-2019-cf7695b470
- DSA-4422
- http://www.apache.org/dist/httpd/CHANGES_2.4.39
- https://support.f5.com/csp/article/K44591505
- FEDORA-2019-08e57d15fd
- FEDORA-2019-c7187e6dc7
- RHSA-2019:3933
- RHSA-2019:3935
- RHSA-2019:3932
Other 19
- [httpd-cvs] 20190611 svn commit: r1861068 - /httpd/site/trunk/content/security/vulnerabilities-httpd.xml
- [httpd-cvs] 20190611 svn commit: r1046148 - in /websites/production/httpd/content: ./ mail
- https://security.netapp.com/advisory/ntap-20190617-0002/
- https://www.oracle.com/technetwork/security-advisory/cpujul2019-5072835.html
- [httpd-cvs] 20190815 svn commit: r1048743 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20190815 svn commit: r1048742 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03950en_us
- https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
- [httpd-cvs] 20200401 svn commit: r1058586 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20200401 svn commit: r1058587 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/vulnerabilities-httpd.xml security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- https://www.oracle.com/security-alerts/cpuapr2020.html
- [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/
- [httpd-cvs] 20210330 svn commit: r1073143 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/
- [httpd-cvs] 20210330 svn commit: r1073140 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/cvejsontohtml.py security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
- [httpd-cvs] 20210330 svn commit: r1073139 [12/13] - in /websites/staging/httpd/trunk/content: ./ security/json/
- [httpd-cvs] 20210330 svn commit: r1888194 [12/13] - /httpd/site/trunk/content/security/json/
- [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/
- [httpd-cvs] 20210330 svn commit: r1073149 [12/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/
- [httpd-cvs] 20210606 svn commit: r1075470 [4/4] - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2020-13938.json security/vulnerabilities_13.html security/vulnerabilities_20.html security/vulnerabilities_22.html security/vulnerabilities_24.html
More Apache Http Server vulnerabilities
- TI-2021-18535 Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) KEVCVSS 3.1CRITICAL 9.8
- TI-2021-18417 Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 KEVCVSS 3.1CRITICAL 9.8
- TI-2024-25716 Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path. KEVCVSS 3.1CRITICAL 9.1
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
- TI-2019-00184 Use after free in Apache HTTP Server KEVCVSS 3.1HIGH 7.8
- TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
Sources
- CVE-2019-0196 · CVE Program
- CVE-2019-0196 · NVD
- FIRST EPSS
- GHSA-vqc7-p7p7-97wf · GitHub Advisory Database · CC BY 4.0
- CVE-2019-0196 · Red Hat security data · CC BY 4.0
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