xzgrep: arbitrary-file-write vulnerability (#2073310, CVE-2022-1271)

sources

@@ -1,2 +1,3 @@
 SHA512 (xz-5.2.5.tar.xz) = 59266068a51cb616eb31b67cd8f07ffeb2288d1391c61665ae2ec6814465afac80fec69248f6a2f2db45b44475af001296a99af6a32287226a9c41419173ccbb
 SHA512 (xz-5.2.5.tar.xz.sig) = ea0218ac25843c8b44686871fba573809618f074465ec52f5966a082aeeb5e01bd646d462a56a6af7a786e1c69a05b135a6735ad1f3be27daecf3a2f9be865a5
+SHA512 (xzgrep-ZDI-CAN-16587.patch.sig) = 527c2702cf3ff3ddee6e49feb6d2305e4e9cd786f856b25f0cb5776df1341c5a960ba54c179cb27c507011e1223baf4a10de8a546199806ff96f531f62b9f136

xz.spec

@@ -15,11 +15,16 @@ Source0:	https://tukaani.org/%{name}/%{name}-%{version}.tar.xz
 Source1:	https://tukaani.org/%{name}/%{name}-%{version}.tar.xz.sig
 # https://tukaani.org/misc/lasse_collin_pubkey.txt
 Source2:        gpgkey-3690C240CE51B4670D30AD1C38EE757D69184620.asc
+# Signature for Patch2
+Source3:        https://tukaani.org/%{name}/xzgrep-ZDI-CAN-16587.patch.sig
 
 Source100:	colorxzgrep.sh
 Source101:	colorxzgrep.csh
 
-Patch1:   xz-5.2.5-enable_CET.patch
+Patch1:		xz-5.2.5-enable_CET.patch
+# xzgrep: arbitrary-file-write vulnerability (CVE-2022-1271)
+# NOTE: Source3 contains the upstream signature for this patch
+Patch2:		https://tukaani.org/%{name}/xzgrep-ZDI-CAN-16587.patch
 
 URL:		https://tukaani.org/%{name}/
 Requires:	%{name}-libs%{?_isa} = %{version}-%{release}
@@ -88,6 +93,7 @@ commands that deal with the older LZMA format.
 
 %prep
 %{gpgverify} --keyring='%{SOURCE2}' --signature='%{SOURCE1}' --data='%{SOURCE0}'
+%{gpgverify} --keyring='%{SOURCE2}' --signature='%{SOURCE3}' --data='%{PATCH2}'
 %autosetup -p1
 
 
@@ -163,6 +169,7 @@ LD_LIBRARY_PATH=$PWD/src/liblzma/.libs make check
 %changelog
 * Sat Apr 16 2022 Todd Zullinger <tmz@pobox.com> - 5.2.5-9
 - verify upstream GPG signature
+- xzgrep: arbitrary-file-write vulnerability (#2073310, CVE-2022-1271)
 
 * Sat Jan 22 2022 Fedora Release Engineering <releng@fedoraproject.org> - 5.2.5-8
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_36_Mass_Rebuild

xzgrep-ZDI-CAN-16587.patch

@@ -0,0 +1,94 @@
+From 69d1b3fc29677af8ade8dc15dba83f0589cb63d6 Mon Sep 17 00:00:00 2001
+From: Lasse Collin <lasse.collin@tukaani.org>
+Date: Tue, 29 Mar 2022 19:19:12 +0300
+Subject: [PATCH] xzgrep: Fix escaping of malicious filenames (ZDI-CAN-16587).
+
+Malicious filenames can make xzgrep to write to arbitrary files
+or (with a GNU sed extension) lead to arbitrary code execution.
+
+xzgrep from XZ Utils versions up to and including 5.2.5 are
+affected. 5.3.1alpha and 5.3.2alpha are affected as well.
+This patch works for all of them.
+
+This bug was inherited from gzip's zgrep. gzip 1.12 includes
+a fix for zgrep.
+
+The issue with the old sed script is that with multiple newlines,
+the N-command will read the second line of input, then the
+s-commands will be skipped because it's not the end of the
+file yet, then a new sed cycle starts and the pattern space
+is printed and emptied. So only the last line or two get escaped.
+
+One way to fix this would be to read all lines into the pattern
+space first. However, the included fix is even simpler: All lines
+except the last line get a backslash appended at the end. To ensure
+that shell command substitution doesn't eat a possible trailing
+newline, a colon is appended to the filename before escaping.
+The colon is later used to separate the filename from the grep
+output so it is fine to add it here instead of a few lines later.
+
+The old code also wasn't POSIX compliant as it used \n in the
+replacement section of the s-command. Using \<newline> is the
+POSIX compatible method.
+
+LC_ALL=C was added to the two critical sed commands. POSIX sed
+manual recommends it when using sed to manipulate pathnames
+because in other locales invalid multibyte sequences might
+cause issues with some sed implementations. In case of GNU sed,
+these particular sed scripts wouldn't have such problems but some
+other scripts could have, see:
+
+    info '(sed)Locale Considerations'
+
+This vulnerability was discovered by:
+cleemy desu wayo working with Trend Micro Zero Day Initiative
+
+Thanks to Jim Meyering and Paul Eggert discussing the different
+ways to fix this and for coordinating the patch release schedule
+with gzip.
+---
+ src/scripts/xzgrep.in | 20 ++++++++++++--------
+ 1 file changed, 12 insertions(+), 8 deletions(-)
+
+diff --git a/src/scripts/xzgrep.in b/src/scripts/xzgrep.in
+index b180936..e5186ba 100644
+--- a/src/scripts/xzgrep.in
++++ b/src/scripts/xzgrep.in
+@@ -180,22 +180,26 @@ for i; do
+          { test $# -eq 1 || test $no_filename -eq 1; }; then
+       eval "$grep"
+     else
++      # Append a colon so that the last character will never be a newline
++      # which would otherwise get lost in shell command substitution.
++      i="$i:"
++
++      # Escape & \ | and newlines only if such characters are present
++      # (speed optimization).
+       case $i in
+       (*'
+ '* | *'&'* | *'\'* | *'|'*)
+-        i=$(printf '%s\n' "$i" |
+-            sed '
+-              $!N
+-              $s/[&\|]/\\&/g
+-              $s/\n/\\n/g
+-            ');;
++        i=$(printf '%s\n' "$i" | LC_ALL=C sed 's/[&\|]/\\&/g; $!s/$/\\/');;
+       esac
+-      sed_script="s|^|$i:|"
++
++      # $i already ends with a colon so don't add it here.
++      sed_script="s|^|$i|"
+ 
+       # Fail if grep or sed fails.
+       r=$(
+         exec 4>&1
+-        (eval "$grep" 4>&-; echo $? >&4) 3>&- | sed "$sed_script" >&3 4>&-
++        (eval "$grep" 4>&-; echo $? >&4) 3>&- |
++            LC_ALL=C sed "$sed_script" >&3 4>&-
+       ) || r=2
+       exit $r
+     fi >&3 5>&-
+-- 
+2.35.1
+