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Bump xz to 5.2.5 and gzip to 1.12 Fixes CVE-2022-1271, ZDI-CAN-16587 ```text 5.2.5 was released on 2020-03-17. A patch to fix a security vulnerability in xzgrep (CVE-2022-1271, ZDI-CAN-16587) was made public on 2022-04-07. It is a severe issue if an attacker can control the filenames that are given on the xzgrep command line. ``` Ref: - https://tukaani.org/xz/ - https://www.openwall.com/lists/oss-security/2022/04/07/8 Signed-off-by: Noel Georgi <[email protected]>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,93 @@ | ||
| From 69d1b3fc29677af8ade8dc15dba83f0589cb63d6 Mon Sep 17 00:00:00 2001 | ||
| From: Lasse Collin <[email protected]> | ||
| Date: Tue, 29 Mar 2022 19:19:12 +0300 | ||
| Subject: [PATCH] xzgrep: Fix escaping of malicious filenames (ZDI-CAN-16587). | ||
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| Malicious filenames can make xzgrep to write to arbitrary files | ||
| or (with a GNU sed extension) lead to arbitrary code execution. | ||
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| 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. | ||
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| This bug was inherited from gzip's zgrep. gzip 1.12 includes | ||
| a fix for zgrep. | ||
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| 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. | ||
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| 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. | ||
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| 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. | ||
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| 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: | ||
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| info '(sed)Locale Considerations' | ||
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| This vulnerability was discovered by: | ||
| cleemy desu wayo working with Trend Micro Zero Day Initiative | ||
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| 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(-) | ||
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| 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|" | ||
|
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||
| # 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 |
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