Upstream: https://github.com/sergiomb2/libmp4v2/commit/9084868fd9f86bee118001c23171e832f15009f4 Gentoo Bug: https://bugs.gentoo.org/661582 From 9084868fd9f86bee118001c23171e832f15009f4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=A9rgio=20M=2E=20Basto?= Date: Fri, 8 Nov 2019 02:01:32 +0000 Subject: [PATCH] Fix v3 Integer underflow/overflow in MP4v2 2.0.0 Reference: https://www.openwall.com/lists/oss-security/2018/07/16/1 For the overflow, we could check the result of the integer multiplication: fix vulnerability where an atom list size is enormous and calculating the number of bytes needed to hold the list overflows https://github.com/TechSmith/mp4v2/pull/27/commits/70d823ccd8e2d7d0ed9e62fb7e8983d21e6acbeb Addresses https://nvd.nist.gov/vuln/detail/CVE-2018-14326 and https://nvd.nist.gov/vuln/detail/CVE-2018-14446 For the underflow, we could check if `dataSize >= hdrSize` satisfies: Throw exception when invalid atom size would cause integer underflow The calculation `hdrSize - dataSize` can underflow the 64-bit unsigned int dataSize type, which can lead to incorrect results. We throw an exception to stop the code from going any further. Addresses https://nvd.nist.gov/vuln/detail/CVE-2018-14325 Based on https://github.com/TechSmith/mp4v2/commit/e475013c6ef78093055a02b0d035eda0f9f01451 --- src/mp4array.h | 2 ++ src/mp4atom.cpp | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/src/mp4array.h b/src/mp4array.h index c49d59b..69d470a 100644 --- a/src/mp4array.h +++ b/src/mp4array.h @@ -102,6 +102,8 @@ class MP4Array { void Resize(MP4ArrayIndex newSize) { \ m_numElements = newSize; \ m_maxNumElements = newSize; \ + if ( (uint64_t) m_maxNumElements * sizeof(type) > 0xFFFFFFFF ) \ + throw new PlatformException("requested array size exceeds 4GB", ERANGE, __FILE__, __LINE__, __FUNCTION__); /* prevent overflow */ \ m_elements = (type*)MP4Realloc(m_elements, \ m_maxNumElements * sizeof(type)); \ } \ diff --git a/src/mp4atom.cpp b/src/mp4atom.cpp index 7a0a53f..f5d5dc0 100644 --- a/src/mp4atom.cpp +++ b/src/mp4atom.cpp @@ -143,6 +143,12 @@ MP4Atom* MP4Atom::ReadAtom(MP4File& file, MP4Atom* pParentAtom) dataSize = file.GetSize() - pos; } + if(dataSize < hdrSize) { + ostringstream oss; + oss << "Invalid atom size in '" << type << "' atom, dataSize = " << dataSize << " cannot be less than hdrSize = " << static_cast( hdrSize ); + log.errorf( "%s: \"%s\": %s", __FUNCTION__, file.GetFilename().c_str(), oss.str().c_str() ); + throw new Exception( oss.str().c_str(), __FILE__, __LINE__, __FUNCTION__ ); + } dataSize -= hdrSize; log.verbose1f("\"%s\": type = \"%s\" data-size = %" PRIu64 " (0x%" PRIx64 ") hdr %u",