In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and…

Description

In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 protocol.

Scores

EPSS (exploitation in 30 days)

51.0% · top 1.1% of all CVEs (6 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.

Weakness

• mod_http2, DoS via continuous SETTINGS frames

Affected products

• Apache Software Foundation · Apache HTTP Server

  • affected 2.4.17 to 2.4.34

References (26)

• https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html (opens in a new tab)x_refsource_CONFIRMx_transferred
• RHSA-2018:3558 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
• 105414 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
• https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03909en_us (opens in a new tab)x_refsource_CONFIRMx_transferred
• https://security.netapp.com/advisory/ntap-20190204-0004/ (opens in a new tab)x_refsource_CONFIRMx_transferred
• RHSA-2019:0367 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
• USN-3783-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
• https://httpd.apache.org/security/vulnerabilities_24.html (opens in a new tab)x_refsource_CONFIRMx_transferred
• 1041713 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
• RHSA-2019:0366 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
• https://www.oracle.com/technetwork/security-advisory/cpuapr2019-5072813.html (opens in a new tab)x_refsource_MISCx_transferred
• openSUSE-SU-2019:1547 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
• openSUSE-SU-2019:1814 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
• [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 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [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 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• https://www.tenable.com/security/tns-2019-09 (opens in a new tab)x_refsource_CONFIRMx_transferred
• [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 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [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 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [httpd-cvs] 20210330 svn commit: r1073139 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [httpd-cvs] 20210330 svn commit: r1073143 [3/3] - in /websites/staging/httpd/trunk/content: ./ security/ (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [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 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [httpd-cvs] 20210330 svn commit: r1073139 [11/13] - in /websites/staging/httpd/trunk/content: ./ security/json/ (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [httpd-cvs] 20210330 svn commit: r1888194 [11/13] - /httpd/site/trunk/content/security/json/ (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [httpd-cvs] 20210330 svn commit: r1073149 [1/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [httpd-cvs] 20210330 svn commit: r1073149 [11/13] - in /websites/staging/httpd/trunk/content: ./ security/ security/json/ (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• [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 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2018-11763](https://trackcve.app/badge/CVE-2018-11763.svg)](https://trackcve.app/cve/CVE-2018-11763)

Record last updated 17 Sept 2024, 02:21 UTC.