From 190040ebfcf5395a6ccedede2cc9343d34f0a108 Mon Sep 17 00:00:00 2001 From: mancha Date: Wed, 11 Feb 2015 Subject: Info-ZIP UnZip buffer overflow Upstream-Status: Backport CVE: CVE-2014-9636 By carefully crafting a corrupt ZIP archive with "extra fields" that purport to have compressed blocks larger than the corresponding uncompressed blocks in STORED no-compression mode, an attacker can trigger a heap overflow that can result in application crash or possibly have other unspecified impact. This patch ensures that when extra fields use STORED mode, the "compressed" and uncompressed block sizes match. Signed-off-by: mancha --- extract.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/extract.c +++ b/extract.c @@ -2217,6 +2217,7 @@ static int test_compr_eb(__G__ eb, eb_si ulg eb_ucsize; uch *eb_ucptr; int r; + ush method; if (compr_offset < 4) /* field is not compressed: */ return PK_OK; /* do nothing and signal OK */ @@ -2226,6 +2227,13 @@ static int test_compr_eb(__G__ eb, eb_si eb_size <= (compr_offset + EB_CMPRHEADLEN))) return IZ_EF_TRUNC; /* no compressed data! */ + method = makeword(eb + (EB_HEADSIZE + compr_offset)); + if ((method == STORED) && + (eb_size - compr_offset - EB_CMPRHEADLEN != eb_ucsize)) + return PK_ERR; /* compressed & uncompressed + * should match in STORED + * method */ + if ( #ifdef INT_16BIT (((ulg)(extent)eb_ucsize) != eb_ucsize) ||