deadsimple BSD Security Advisories and Announcements

FreeBSD Security Advisory

Hash: SHA512

=============================================================================                                       Security Advisory
                                                          The FreeBSD Project

Topic:          Stack overflow in ping(8)

Category:       core
Module:         ping
Announced:      2022-11-29
Credits:        Tom Jones
Affects:        All supported versions of FreeBSD.
Corrected:      2022-11-29 22:56:33 UTC (stable/13, 13.1-STABLE)
                2022-11-29 23:00:43 UTC (releng/13.1, 13.1-RELEASE-p5)
                2022-11-29 22:57:16 UTC (stable/12, 12.4-STABLE)
                2022-11-29 23:19:09 UTC (releng/12.4, 12.4-RC2-p2)
                2022-11-29 23:16:17 UTC (releng/12.3, 12.3-RELEASE-p10)
CVE Name:       CVE-2022-23093

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:>.

I.   Background

ping(8) is a program that can be used to test reachability of a remote
host using ICMP messages.  To send and receive ICMP messages, ping makes
use of raw sockets and therefore requires elevated privileges.  To make
ping's functionality available to unprivileged users, it is installed
with the setuid bit set.  When ping runs, it creates the raw socket
needed to do its work, and then revokes its elevated privileges. 

II.  Problem Description

ping reads raw IP packets from the network to process responses in the
pr_pack() function.  As part of processing a response ping has to
reconstruct the IP header, the ICMP header and if present a "quoted
packet," which represents the packet that generated an ICMP error.  The
quoted packet again has an IP header and an ICMP header.

The pr_pack() copies received IP and ICMP headers into stack buffers
for further processing.  In so doing, it fails to take into account the
possible presence of IP option headers following the IP header in
either the response or the quoted packet.  When IP options are present,
pr_pack() overflows the destination buffer by up to 40 bytes.

III. Impact

The memory safety bugs described above can be triggered by a remote
host, causing the ping program to crash.  It may be possible for a
malicious host to trigger remote code execution in ping.

The ping process runs in a capability mode sandbox on all affected
versions of FreeBSD and is thus very constrainted in how it can interact
with the rest of the system at the point where the bug can occur.

IV.  Workaround

No workaround is available.

V.   Solution

Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.

Perform one of the following:

1) To update your vulnerable system via a binary patch:

Systems running a RELEASE version of FreeBSD on the amd64, i386, or
(on FreeBSD 13 and later) arm64 platforms can be updated via the
freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

2) To update your vulnerable system via a source code patch:

The following patches have been verified to apply to the applicable
FreeBSD release branches.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch
# fetch
# gpg --verify ping.patch.asc

b) Apply the patch.  Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

c) Recompile the operating system using buildworld and installworld as
described in <URL:>.

VI.  Correction details

This issue is corrected by the corresponding Git commit hash or Subversion
revision number in the following stable and release branches:

Branch/path                             Hash                     Revision
- -------------------------------------------------------------------------
stable/13/                              186f495d4be1    stable/13-n253187
releng/13.1/                            66c7b53d9516  releng/13.1-n250172
stable/12/                                                        r372774
releng/12.4/                                                      r372778
releng/12.3/                                                      r372775
- -------------------------------------------------------------------------

For FreeBSD 13 and later:

Run the following command to see which files were modified by a
particular commit:

# git show --stat <commit hash>

Or visit the following URL, replacing NNNNNN with the hash:


To determine the commit count in a working tree (for comparison against
nNNNNNN in the table above), run:

# git rev-list --count --first-parent HEAD

For FreeBSD 12 and earlier:

Run the following command to see which files were modified by a particular
revision, replacing NNNNNN with the revision number:

# svn diff -cNNNNNN --summarize svn://

Or visit the following URL, replacing NNNNNN with the revision number:


VII. References


The latest revision of this advisory is available at