What’s Vulnerable › Vulnerabilities

CVE-2020-13950: mod_proxy_http NULL pointer dereference

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 49.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-10 · updated 2026-06-17
• Weakness: CWE-476

Description

Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers, leading to a Denial of Service

Affected products

• Apache HTTP Server: from 2.4.41 through 2.4.46
• Debian Linux: 9.0, 10.0
• Fedoraproject Fedora: 34, 35
• Oracle Corporation Enterprise Manager Ops Center: 12.4.0.0
• Oracle Instantis Enterprisetrack: 17.1, 17.2, 17.3
• Oracle Corporation Oracle ZFS Storage Appliance Kit: 8.8

References

• http://httpd.apache.org/security/vulnerabilities_24.html
• http://www.openwall.com/lists/oss-security/2021/06/10/4
• https://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd%40%3Cdev.httpd.apache.org%3E
• https://lists.apache.org/thread.html/rbe197409ae4a58b629fb792d1aed541ccbbf865121a80e1c5938d223%40%3Cannounce.httpd.apache.org%3E
• https://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3E
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
• https://security.gentoo.org/glsa/202107-38
• https://security.netapp.com/advisory/ntap-20210702-0001/
• https://www.oracle.com/security-alerts/cpuoct2021.html
• http://httpd.apache.org/security/vulnerabilities_24.html
• http://www.openwall.com/lists/oss-security/2021/06/10/4

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