0012-Info-ZIP-UnZip-buffer-overflow.patch (1834B)
- From 14342a8a5ddafa76a8aa9800da078d415f50af71 Mon Sep 17 00:00:00 2001
- From: mancha <mancha1@zoho.com>
- Date: Wed, 11 Feb 2015 12:27:06 +0000
- Subject: [PATCH] Info-ZIP UnZip buffer overflow
- 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.
- ---
- extract.c | 10 ++++++++++
- 1 file changed, 10 insertions(+)
- diff --git a/extract.c b/extract.c
- index ec31e60..f951b9f 100644
- --- a/extract.c
- +++ b/extract.c
- @@ -2228,6 +2228,7 @@ static int test_compr_eb(__G__ eb, eb_size, compr_offset, test_uc_ebdata)
- ulg eb_ucsize;
- uch *eb_ucptr;
- int r;
- + ush eb_compr_method;
- if (compr_offset < 4) /* field is not compressed: */
- return PK_OK; /* do nothing and signal OK */
- @@ -2244,6 +2245,15 @@ static int test_compr_eb(__G__ eb, eb_size, compr_offset, test_uc_ebdata)
- ((eb_ucsize > 0L) && (eb_size <= (compr_offset + EB_CMPRHEADLEN))))
- return IZ_EF_TRUNC; /* no/bad compressed data! */
- + /* 2015-02-10 Mancha(?), Michal Zalewski, Tomas Hoger, SMS.
- + * For STORE method, compressed and uncompressed sizes must agree.
- + * http://www.info-zip.org/phpBB3/viewtopic.php?f=7&t=450
- + */
- + eb_compr_method = makeword( eb + (EB_HEADSIZE + compr_offset));
- + if ((eb_compr_method == STORED) &&
- + (eb_size != compr_offset + EB_CMPRHEADLEN + eb_ucsize))
- + return PK_ERR;
- +
- if (
- #ifdef INT_16BIT
- (((ulg)(extent)eb_ucsize) != eb_ucsize) ||
- --
- 2.20.1