From 7f2da4f810b429ddb7afa0e252e3d02ced0eba87 Mon Sep 17 00:00:00 2001 From: Radovan Scasny Date: Tue, 20 Feb 2018 12:08:13 +0100 Subject: [PATCH] p7zip: Fix CVE-2017-17969 [No upstream tracking] -- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=888297 Heap-based buffer overflow in 7zip Compress/ShrinkDecoder.cpp: Heap-based buffer overflow in the NCompress::NShrink::CDecoder::CodeReal method in 7-Zip before 18.00 and p7zip allows remote attackers to cause a denial of service (out-of-bounds write) or potentially execute arbitrary code via a crafted ZIP archive. Upstream-Status: Backport [https://sourceforge.net/p/p7zip/bugs/_discuss/thread/0920f369/8316/attachment/CVE-2017-17969.patch] CVE: CVE-2017-17969 Signed-off-by: Radovan Scasny --- CPP/7zip/Compress/ShrinkDecoder.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/CPP/7zip/Compress/ShrinkDecoder.cpp b/CPP/7zip/Compress/ShrinkDecoder.cpp index 80b7e67..5bb0559 100644 --- a/CPP/7zip/Compress/ShrinkDecoder.cpp +++ b/CPP/7zip/Compress/ShrinkDecoder.cpp @@ -121,7 +121,12 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream * { _stack[i++] = _suffixes[cur]; cur = _parents[cur]; + if (cur >= kNumItems || i >= kNumItems) + break; } + + if (cur >= kNumItems || i >= kNumItems) + break; _stack[i++] = (Byte)cur; lastChar2 = (Byte)cur;