Synopsis
The remote Red Hat host is missing a security update for httpd.
Description
The remote Redhat Enterprise Linux 6 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2017:1721 advisory.
The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.
Security Fix(es):
* It was discovered that the HTTP parser in httpd incorrectly allowed certain characters not permitted by the HTTP protocol specification to appear unencoded in HTTP request headers. If httpd was used in conjunction with a proxy or backend server that interpreted those characters differently, a remote attacker could possibly use this flaw to inject data into HTTP responses, resulting in proxy cache poisoning. (CVE-2016-8743)
Note: The fix for the CVE-2016-8743 issue causes httpd to return 400 Bad Request error to HTTP clients which do not strictly follow HTTP protocol specification. A newly introduced configuration directive HttpProtocolOptions Unsafe can be used to re-enable the old less strict parsing. However, such setting also re-introduces the CVE-2016-8743 issue.
Note: Administrators of Red Hat Satellite 5 and Red Hat Satellite Proxy 5 systems should consult Red Hat Knowledgebase article 3013361 linked to in the Reference section before installing this update.
Bug Fix(es):
* Previously, httpd was unable to correctly check a boundary of an array, and in rare cases it attempted to access an element of an array that was out of bounds. Consequently, httpd terminated unexpectedly with a segmentation fault at proxy_util.c. With this update, bounds checking has been fixed, and httpd no longer crashes. (BZ#1463354)
Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Update the RHEL httpd package based on the guidance in RHSA-2017:1721.
Plugin Details
File Name: redhat-RHSA-2017-1721.nasl
Agent: unix
Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus
Risk Information
Vendor
Vendor Severity: Moderate
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
CPE: p-cpe:/a:redhat:enterprise_linux:httpd-devel, p-cpe:/a:redhat:enterprise_linux:mod_ssl, p-cpe:/a:redhat:enterprise_linux:httpd-tools, cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:redhat:enterprise_linux:httpd-manual, p-cpe:/a:redhat:enterprise_linux:httpd
Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu
Exploit Ease: No known exploits are available
Patch Publication Date: 7/11/2017
Vulnerability Publication Date: 7/27/2017