From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CE3A0C433EF for ; Tue, 19 Apr 2022 17:27:23 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 56754418AD; Tue, 19 Apr 2022 17:27:23 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mHXyzAi3MVFe; Tue, 19 Apr 2022 17:27:21 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by smtp4.osuosl.org (Postfix) with ESMTP id 06C5A4185A; Tue, 19 Apr 2022 17:27:20 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by ash.osuosl.org (Postfix) with ESMTP id AA1121BF293 for ; Tue, 19 Apr 2022 17:27:17 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 9203483FE7 for ; Tue, 19 Apr 2022 17:27:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hDiu98MVASt7 for ; Tue, 19 Apr 2022 17:27:16 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from mout-b-110.mailbox.org (mout-b-110.mailbox.org [195.10.208.55]) by smtp1.osuosl.org (Postfix) with ESMTPS id 4D4F483F40 for ; Tue, 19 Apr 2022 17:27:16 +0000 (UTC) Received: from smtp1.mailbox.org (smtp1.mailbox.org [80.241.60.240]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-b-110.mailbox.org (Postfix) with ESMTPS id 4KjW2R6vdyz9smQ for ; Tue, 19 Apr 2022 19:27:11 +0200 (CEST) Message-ID: <6b8513cd-399a-ddfe-2587-a933b6cf0fe6@othermo.de> Date: Tue, 19 Apr 2022 19:27:06 +0200 MIME-Version: 1.0 Content-Language: en-US To: buildroot@buildroot.org References: <20220419111714.1647112-1-marcus.hoffmann@othermo.de> <20220419111714.1647112-2-marcus.hoffmann@othermo.de> <87tuapqaqw.fsf@tarshish> From: Marcus Hoffmann In-Reply-To: <87tuapqaqw.fsf@tarshish> Subject: Re: [Buildroot] [PATCH 2/2] package/xz: backport CVE-2022-1271 security fix X-BeenThere: buildroot@buildroot.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion and development of buildroot List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: buildroot-bounces@buildroot.org Sender: "buildroot" Hi Baruch, On 19.04.22 18:47, Baruch Siach via buildroot wrote: > Hi Marcus, > > On Tue, Apr 19 2022, Marcus Hoffmann wrote: >> Fixes the following security issue: >> >> CVE-2022-1271/ZDI-22-619/ZDI-CAN-16587: arbitrary-file-write vulnerability >> >> 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. >> >> This vulnerability was discovered by: >> cleemy desu wayo working with Trend Micro Zero Day Initiative >> >> https://www.mail-archive.com/xz-devel@tukaani.org/msg00551.html >> https://www.zerodayinitiative.com/advisories/ZDI-22-619/ >> https://www.openwall.com/lists/oss-security/2022/04/07/8 >> Signed-off-by: Marcus Hoffmann >> --- >> package/xz/0001-xzgrep-ZDI-CAN-16587.patch | 96 ++++++++++++++++++++++ >> 1 file changed, 96 insertions(+) >> create mode 100644 package/xz/0001-xzgrep-ZDI-CAN-16587.patch > > This patch should also add XZ_IGNORE_CVES in xz.mk. > > baruch Indeed! But Peter already send a better patch that does this: https://patchwork.ozlabs.org/project/buildroot/patch/20220419113409.1008586-1-peter@korsgaard.com/ Marcus > >> >> diff --git a/package/xz/0001-xzgrep-ZDI-CAN-16587.patch b/package/xz/0001-xzgrep-ZDI-CAN-16587.patch >> new file mode 100644 >> index 0000000000..78ee9640f0 >> --- /dev/null >> +++ b/package/xz/0001-xzgrep-ZDI-CAN-16587.patch >> @@ -0,0 +1,96 @@ >> +From 69d1b3fc29677af8ade8dc15dba83f0589cb63d6 Mon Sep 17 00:00:00 2001 >> +From: Lasse Collin >> +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 \ 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. >> + >> +Signed-off-by: Marcus Hoffmann >> +--- >> + 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 >> + > > _______________________________________________ buildroot mailing list buildroot@buildroot.org https://lists.buildroot.org/mailman/listinfo/buildroot