CVE-2017-15710: Apache HTTP Server

High severity, CVSS 7.5. EPSS: 17.1% chance of exploitation in the next 30 days.

In Apache httpd 2.0.23 to 2.0.65, 2.2.0 to 2.2.34, and 2.4.0 to 2.4.29, mod_authnz_ldap, if configured with AuthLDAPCharsetConfig, uses the Accept-Language header value to lookup the right charset encoding when verifying the user's credentials. If the header value is not present in the charset conversion table, a fallback mechanism is used to truncate it to a two characters value to allow a quick retry (for example, 'en-US' is truncated to 'en'). A header value of less than two characters forces an out of bound write of one NUL byte to a memory location that is not part of the string. In the worst case, quite unlikely, the process would crash which could be used as a Denial of Service attack. In the more likely case, this memory is already reserved for future use and the issue has no effect at all.

Affected products

• Apache HTTP Server: version 2.4.1 only; version 2.4.2 only; version 2.4.3 only; version 2.4.4 only; version 2.4.6 only; version 2.4.7 only; …
• Canonical Ubuntu Linux: version 12.04 only; version 14.04 only; version 16.04 only; version 17.10 only; version 18.04 only
• Debian Debian Linux: version 7.0 only; version 8.0 only; version 9.0 only
• Netapp Clustered Data Ontap: affected versions not specified
• Netapp Santricity Cloud Connector: affected versions not specified
• Netapp Storage Automation Store: affected versions not specified
• Netapp Storagegrid: affected versions not specified
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 7.4 only; version 7.5 only; version 7.6 only

Published 2018-03-26. Last modified 2026-06-17.