CVE-2017-9788: Apache HTTP Server

Critical severity, CVSS 9.1. EPSS: 56.8% chance of exploitation in the next 30 days.

In Apache httpd before 2.2.34 and 2.4.x before 2.4.27, the value placeholder in [Proxy-]Authorization headers of type 'Digest' was not initialized or reset before or between successive key=value assignments by mod_auth_digest. Providing an initial key with no '=' assignment could reflect the stale value of uninitialized pool memory used by the prior request, leading to leakage of potentially confidential information, and a segfault in other cases resulting in denial of service.

Affected products

• Apache HTTP Server: up to and including 2.2.33; from 2.4.0, up to and including 2.4.26
• Apple Mac OS X: before 10.13.1 (fixed in 10.13.1)
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Netapp Oncommand Unified Manager: affected versions not specified
• Netapp Storage Automation Store: affected versions not specified
• Oracle Secure Global Desktop: version 5.3 only
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.2 only; version 7.3 only; version 7.4 only; version 7.6 only
• Red Hat Enterprise Linux Server Eus: version 6.7 only; version 7.2 only; version 7.3 only; version 7.4 only; version 7.5 only; version 7.6 only
• Red Hat Enterprise Linux Server Tus: version 7.2 only; version 7.3 only; version 7.4 only; version 7.6 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only
• Red Hat JBoss Core Services: version 1.0 only
• Red Hat JBoss Enterprise Application Platform: version 6.0.0 only; version 6.4.0 only
• Red Hat JBoss Enterprise Web Server: version 2.0.0 only

Published 2017-07-13. Last modified 2026-06-17.