[SA18609] FreeBSD "pf" IP Fragment Denial of Service Vulnerability

Type securityvulns
Reporter Securityvulns
Modified 2006-01-25T00:00:00


TITLE: FreeBSD "pf" IP Fragment Denial of Service Vulnerability


VERIFY ADVISORY: http://secunia.com/advisories/18609/

CRITICAL: Moderately critical


WHERE: >From remote

OPERATING SYSTEM: FreeBSD 6.x http://secunia.com/product/6778/ FreeBSD 5.x http://secunia.com/product/1132/

DESCRIPTION: A vulnerability has been reported in FreeBSD, which can be exploited by malicious people to cause a DoS (Denial of Service).

The vulnerability is caused due to an error in the "pf" Internet Protocol packet-filter fragment cache when handling IP fragments. This can be exploited to crash the system by sending a specially-crafted sequence of IP packet fragments to the packet filter.

Successful exploitation requires that "pf" is used with a ruleset containing "scrub fragment crop" or "scrub fragment drop-ovl" rules.

The vulnerability has been reported in version 5.3, 5.4, and 6.0.

SOLUTION: Update FreeBSD or apply patch.

Fixed versions: 2006-01-25 10:00:59 UTC (RELENG_6, 6.0-STABLE) 2006-01-25 10:01:26 UTC (RELENG_6_0, 6.0-RELEASE-p4) 2006-01-25 10:01:47 UTC (RELENG_5, 5.4-STABLE) 2006-01-25 10:02:07 UTC (RELENG_5_4, 5.4-RELEASE-p10) 2006-01-25 10:02:27 UTC (RELENG_5_3, 5.3-RELEASE-p25)

Patch for FreeBSD 5.3, 5.4, and 6.0: ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-06:07/pf.patch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-06:07/pf.patch.asc

PROVIDED AND/OR DISCOVERED BY: The vendor credits Jakob Schlyter and Daniel Hartmeier.

ORIGINAL ADVISORY: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-06:07.pf.asc

About: This Advisory was delivered by Secunia as a free service to help everybody keeping their systems up to date against the latest vulnerabilities.

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