42 lines
1.6 KiB
Diff
42 lines
1.6 KiB
Diff
From 190040ebfcf5395a6ccedede2cc9343d34f0a108 Mon Sep 17 00:00:00 2001
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From: mancha <mancha1 AT zoho DOT com>
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Date: Wed, 11 Feb 2015
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Subject: Info-ZIP UnZip buffer overflow
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By carefully crafting a corrupt ZIP archive with "extra fields" that
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purport to have compressed blocks larger than the corresponding
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uncompressed blocks in STORED no-compression mode, an attacker can
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trigger a heap overflow that can result in application crash or
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possibly have other unspecified impact.
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This patch ensures that when extra fields use STORED mode, the
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"compressed" and uncompressed block sizes match.
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---
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extract.c | 7 +++++++
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1 file changed, 7 insertions(+)
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--- unzip60/extract.c
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+++ unzip60/extract.c
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@@ -2230,6 +2230,7 @@ static int test_compr_eb(__G__ eb, eb_si
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ulg eb_ucsize;
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uch *eb_ucptr;
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int r;
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+ ush method;
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if (compr_offset < 4) /* field is not compressed: */
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return PK_OK; /* do nothing and signal OK */
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@@ -2246,6 +2247,13 @@ static int test_compr_eb(__G__ eb, eb_si
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((eb_ucsize > 0L) && (eb_size <= (compr_offset + EB_CMPRHEADLEN))))
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return IZ_EF_TRUNC; /* no/bad compressed data! */
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+ method = makeword(eb + (EB_HEADSIZE + compr_offset));
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+ if ((method == STORED) &&
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+ (eb_size != compr_offset + EB_CMPRHEADLEN + eb_ucsize))
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+ return PK_ERR; /* compressed & uncompressed
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+ * should match in STORED
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+ * method */
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+
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if (
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#ifdef INT_16BIT
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(((ulg)(extent)eb_ucsize) != eb_ucsize) ||
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