ASA-2019-00270 – FreeBSD: IPv6 fragment reassembly panic in pf(4)


Allele Security Alert

ASA-2019-00270

Identifier(s)

ASA-2019-00270, CVE-2019-5597, FreeBSD-SA-19:05.pf

Title

IPv6 fragment reassembly panic in pf(4)

Vendor(s)

The FreeBSD Project

Product(s)

FreeBSD

Affected version(s)

All supported versions of FreeBSD

Fixed version(s)

2019-03-01 18:12:05 UTC (stable/12, 12.0-STABLE)
2019-05-14 23:10:21 UTC (releng/12.0, 12.0-RELEASE-p4)
2019-03-01 18:12:07 UTC (stable/11, 11.3-PRERELEASE)
2019-05-14 23:10:21 UTC (releng/11.2, 11.2-RELEASE-p10)

Proof of concept

Unknown

Description

A bug in the pf(4) IPv6 fragment reassembly logic incorrectly uses the last extension header offset from the last received packet instead of from the first packet.

Malicious IPv6 packets with different IPv6 extensions could cause a kernel panic or potentially a filtering rule bypass.

Only systems leveraging the pf(4) firewall and include packet scrubbing using the recommended ‘scrub all in’ or similar are affected.

Technical details

Unknown

Credits

Synacktiv

Reference(s)

IPv6 fragment reassembly panic in pf(4)
https://www.freebsd.org/security/advisories/FreeBSD-SA-19:05.pf.asc

CVE-2019-5597
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5597

CVE-2019-5597
https://nvd.nist.gov/vuln/detail/CVE-2019-5597

If there is any error in this alert or you wish a comprehensive analysis, let us know.

Last modified: May 15, 2019

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