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CVE-2021-29623 exiv2: a read of uninitialized memory may lead to information leak

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Resolves: bz#1964183

CVE-2021-32617 exiv2: DoS due to quadratic complexity in ProcessUTF8Portion
Resolves: bz#1964189
This commit is contained in:
Jan Grulich 2021-05-25 12:12:53 +02:00
parent 4c8da3ae72
commit 99c067b851
3 changed files with 161 additions and 1 deletions
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26
exiv2-CVE-2021-29623.patch Normal file
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@ -0,0 +1,26 @@
From 82e46b5524fb904e6660dadd2c6d8e5e47375a1a Mon Sep 17 00:00:00 2001
From: Kevin Backhouse <kevinbackhouse@github.com>
Date: Tue, 11 May 2021 12:14:33 +0100
Subject: [PATCH] Use readOrThrow to check error conditions of iIo.read().
---
src/webpimage.cpp | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/webpimage.cpp b/src/webpimage.cpp
index 7c64ff3d7..ca26e514a 100644
--- a/src/webpimage.cpp
+++ b/src/webpimage.cpp
@@ -754,9 +754,9 @@ namespace Exiv2 {
byte webp[len];
byte data[len];
byte riff[len];
- iIo.read(riff, len);
- iIo.read(data, len);
- iIo.read(webp, len);
+ readOrThrow(iIo, riff, len, Exiv2::kerCorruptedMetadata);
+ readOrThrow(iIo, data, len, Exiv2::kerCorruptedMetadata);
+ readOrThrow(iIo, webp, len, Exiv2::kerCorruptedMetadata);
bool matched_riff = (memcmp(riff, RiffImageId, len) == 0);
bool matched_webp = (memcmp(webp, WebPImageId, len) == 0);
iIo.seek(-12, BasicIo::cur);

125
exiv2-CVE-2021-32617.patch Normal file
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@ -0,0 +1,125 @@
From c261fbaa2567687eec6a595d3016212fd6ae648d Mon Sep 17 00:00:00 2001
From: Kevin Backhouse <kevinbackhouse@github.com>
Date: Sun, 16 May 2021 15:05:08 +0100
Subject: [PATCH] Fix quadratic complexity performance bug.
---
xmpsdk/src/XMPMeta-Parse.cpp | 57 +++++++++++++++++++++++-------------
1 file changed, 36 insertions(+), 21 deletions(-)
diff --git a/xmpsdk/src/XMPMeta-Parse.cpp b/xmpsdk/src/XMPMeta-Parse.cpp
index 9f66fe8..f9c37d7 100644
--- a/xmpsdk/src/XMPMeta-Parse.cpp
+++ b/xmpsdk/src/XMPMeta-Parse.cpp
@@ -976,12 +976,26 @@ ProcessUTF8Portion ( XMLParserAdapter * xmlParser,
{
const XMP_Uns8 * bufEnd = buffer + length;
- const XMP_Uns8 * spanStart = buffer;
const XMP_Uns8 * spanEnd;
-
- for ( spanEnd = spanStart; spanEnd < bufEnd; ++spanEnd ) {
- if ( (0x20 <= *spanEnd) && (*spanEnd <= 0x7E) && (*spanEnd != '&') ) continue; // A regular ASCII character.
+ // `buffer` is copied into this std::string. If `buffer` only
+ // contains valid UTF-8 and no escape characters, then the copy
+ // will be identical to the original, but invalid characters are
+ // replaced - usually with a space character. This std::string was
+ // added as a performance fix for:
+ // https://github.com/Exiv2/exiv2/security/advisories/GHSA-w8mv-g8qq-36mj
+ // Previously, the code was repeatedly calling
+ // `xmlParser->ParseBuffer()`, which turned out to have quadratic
+ // complexity, because expat kept reparsing the entire string from
+ // the beginning.
+ std::string copy;
+
+ for ( spanEnd = buffer; spanEnd < bufEnd; ++spanEnd ) {
+
+ if ( (0x20 <= *spanEnd) && (*spanEnd <= 0x7E) && (*spanEnd != '&') ) {
+ copy.push_back(*spanEnd);
+ continue; // A regular ASCII character.
+ }
if ( *spanEnd >= 0x80 ) {
@@ -992,21 +1006,20 @@ ProcessUTF8Portion ( XMLParserAdapter * xmlParser,
if ( uniLen > 0 ) {
// A valid UTF-8 character, keep it as-is.
+ copy.append((const char*)spanEnd, uniLen);
spanEnd += uniLen - 1; // ! The loop increment will put back the +1.
} else if ( (uniLen < 0) && (! last) ) {
// Have a partial UTF-8 character at the end of the buffer and more input coming.
- xmlParser->ParseBuffer ( spanStart, (spanEnd - spanStart), false );
+ xmlParser->ParseBuffer ( copy.c_str(), copy.size(), false );
return (spanEnd - buffer);
} else {
// Not a valid UTF-8 sequence. Replace the first byte with the Latin-1 equivalent.
- xmlParser->ParseBuffer ( spanStart, (spanEnd - spanStart), false );
const char * replacement = kReplaceLatin1 [ *spanEnd - 0x80 ];
- xmlParser->ParseBuffer ( replacement, strlen ( replacement ), false );
- spanStart = spanEnd + 1; // ! The loop increment will do "spanEnd = spanStart".
+ copy.append ( replacement );
}
@@ -1014,11 +1027,12 @@ ProcessUTF8Portion ( XMLParserAdapter * xmlParser,
// Replace ASCII controls other than tab, LF, and CR with a space.
- if ( (*spanEnd == kTab) || (*spanEnd == kLF) || (*spanEnd == kCR) ) continue;
+ if ( (*spanEnd == kTab) || (*spanEnd == kLF) || (*spanEnd == kCR) ) {
+ copy.push_back(*spanEnd);
+ continue;
+ }
- xmlParser->ParseBuffer ( spanStart, (spanEnd - spanStart), false );
- xmlParser->ParseBuffer ( " ", 1, false );
- spanStart = spanEnd + 1; // ! The loop increment will do "spanEnd = spanStart".
+ copy.push_back(' ');
} else {
@@ -1030,18 +1044,21 @@ ProcessUTF8Portion ( XMLParserAdapter * xmlParser,
if ( escLen < 0 ) {
// Have a partial numeric escape in this buffer, wait for more input.
- if ( last ) continue; // No more buffers, not an escape, absorb as normal input.
- xmlParser->ParseBuffer ( spanStart, (spanEnd - spanStart), false );
+ if ( last ) {
+ copy.push_back('&');
+ continue; // No more buffers, not an escape, absorb as normal input.
+ }
+ xmlParser->ParseBuffer ( copy.c_str(), copy.size(), false );
return (spanEnd - buffer);
} else if ( escLen > 0 ) {
// Have a complete numeric escape to replace.
- xmlParser->ParseBuffer ( spanStart, (spanEnd - spanStart), false );
- xmlParser->ParseBuffer ( " ", 1, false );
- spanStart = spanEnd + escLen;
- spanEnd = spanStart - 1; // ! The loop continuation will increment spanEnd!
+ copy.push_back(' ');
+ spanEnd = spanEnd + escLen - 1; // ! The loop continuation will increment spanEnd!
+ } else {
+ copy.push_back('&');
}
}
@@ -1050,8 +1067,8 @@ ProcessUTF8Portion ( XMLParserAdapter * xmlParser,
XMP_Assert ( spanEnd == bufEnd );
- if ( spanStart < bufEnd ) xmlParser->ParseBuffer ( spanStart, (spanEnd - spanStart), false );
- if ( last ) xmlParser->ParseBuffer ( " ", 1, true );
+ copy.push_back(' ');
+ xmlParser->ParseBuffer ( copy.c_str(), copy.size(), true );
return length;

11
exiv2.spec
View File

@ -5,7 +5,7 @@ Summary: Exif and Iptc metadata manipulation library
Name: exiv2
Version: 0.27.3
%global internal_ver %{version}
Release: 7%{?dist}
Release: 8%{?dist}
License: GPLv2+
URL: http://www.exiv2.org/
@ -23,6 +23,8 @@ Patch51: exiv2-CVE-2021-29457.patch
Patch52: exiv2-CVE-2021-29458.patch
Patch53: exiv2-CVE-2021-29470.patch
Patch54: exiv2-CVE-2021-29473.patch
Patch55: exiv2-CVE-2021-29623.patch
Patch56: exiv2-CVE-2021-32617.patch
## upstreamable patches
# don't unconditionally use -fcf-protection flag, not supported on all archs
@ -142,6 +144,13 @@ test -x %{buildroot}%{_libdir}/libexiv2.so
%changelog
* Tue May 25 2021 Jan Grulich <jgrulich@redhat.com> - 0.27.3-8
- CVE-2021-29623 exiv2: a read of uninitialized memory may lead to information leak
Resolves: bz#1964183
- CVE-2021-32617 exiv2: DoS due to quadratic complexity in ProcessUTF8Portion
Resolves: bz#1964189
* Mon May 03 2021 Jan Grulich <jgrulich@redhat.com> - 0.27.3-7
- CVE-2021-3482: Fix heap-based buffer overflow in Jp2Image::readMetadata()
CVE-2021-29458 exiv2: out-of-bounds read in Exiv2::Internal::CrwMap::encode