CVE-2016-10270 (published 2017-03-24T19:59Z)

LibTIFF 4.0.7 allows remote attackers to cause a denial of service (heap-based buffer over-read) or possibly have unspecified other impact via a crafted TIFF image, related to "READ of size 8" and libtiff/tif_read.c:523:22.

Severity: MEDIUM
CVSS v2 base score: 6.8 (AV:N/AC:M/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 7.8, HIGH (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-125
cwe_name: Out-of-bounds Read
description: The product reads data past the end, or before the beginning, of the intended buffer.
extended_description: 
            
            
             
			 
         
         

Fix information:
repo_url: https://github.com/vadz/libtiff
commit_details: repo_url: https://github.com/vadz/libtiff
author: erouault
author_date: 2016-12-03 11:02:15+00:00
msg: * libtiff/tif_dirread.c: modify ChopUpSingleUncompressedStrip() to
instanciate compute ntrips as TIFFhowmany_32(td->td_imagelength, rowsperstrip),
instead of a logic based on the total size of data. Which is faulty is
the total size of data is not sufficient to fill the whole image, and thus
results in reading outside of the StripByCounts/StripOffsets arrays when
using TIFFReadScanline().
Reported by Agostino Sarubbo.
Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2608.

* libtiff/tif_strip.c: revert the change in TIFFNumberOfStrips() done
for http://bugzilla.maptools.org/show_bug.cgi?id=2587 / CVE-2016-9273 since
the above change is a better fix that makes it unnecessary.
repository: repo_url: https://github.com/vadz/libtiff
repo_name: vadz/libtiff
description: OBSOLETE and not updated any more libtiff mirror, see website for the new one
repo_language: C
owner: vadz
file_changes: filename: ChangeLog
change_type: ModificationType.MODIFY
diff: @@ -1,3 +1,18 @@
+2016-12-03 Even Rouault <even.rouault at spatialys.com>
+
+	* libtiff/tif_dirread.c: modify ChopUpSingleUncompressedStrip() to
+	instanciate compute ntrips as TIFFhowmany_32(td->td_imagelength, rowsperstrip),
+	instead of a logic based on the total size of data. Which is faulty is
+	the total size of data is not sufficient to fill the whole image, and thus
+	results in reading outside of the StripByCounts/StripOffsets arrays when
+	using TIFFReadScanline().
+	Reported by Agostino Sarubbo.
+	Fixes http://bugzilla.maptools.org/show_bug.cgi?id=2608.
+
+	* libtiff/tif_strip.c: revert the change in TIFFNumberOfStrips() done
+	for http://bugzilla.maptools.org/show_bug.cgi?id=2587 / CVE-2016-9273 since
+	the above change is a better fix that makes it unnecessary.
+
 2016-12-03 Even Rouault <even.rouault at spatialys.com>
 
 	* libtiff/tif_pixarlog.c, libtiff/tif_luv.c: fix heap-based buffer

programming_language: Markdown
filename: tif_dirread.c
change_type: ModificationType.MODIFY
diff: @@ -5502,8 +5502,7 @@ ChopUpSingleUncompressedStrip(TIFF* tif)
 	uint64 rowblockbytes;
 	uint64 stripbytes;
 	uint32 strip;
-	uint64 nstrips64;
-	uint32 nstrips32;
+	uint32 nstrips;
 	uint32 rowsperstrip;
 	uint64* newcounts;
 	uint64* newoffsets;
@@ -5534,18 +5533,17 @@ ChopUpSingleUncompressedStrip(TIFF* tif)
 	    return;
 
 	/*
-	 * never increase the number of strips in an image
+	 * never increase the number of rows per strip
 	 */
 	if (rowsperstrip >= td->td_rowsperstrip)
 		return;
-	nstrips64 = TIFFhowmany_64(bytecount, stripbytes);
-	if ((nstrips64==0)||(nstrips64>0xFFFFFFFF)) /* something is wonky, do nothing. */
-	    return;
-	nstrips32 = (uint32)nstrips64;
+        nstrips = TIFFhowmany_32(td->td_imagelength, rowsperstrip);
+        if( nstrips == 0 )
+            return;
 
-	newcounts = (uint64*) _TIFFCheckMalloc(tif, nstrips32, sizeof (uint64),
+	newcounts = (uint64*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64),
 				"for chopped \"StripByteCounts\" array");
-	newoffsets = (uint64*) _TIFFCheckMalloc(tif, nstrips32, sizeof (uint64),
+	newoffsets = (uint64*) _TIFFCheckMalloc(tif, nstrips, sizeof (uint64),
 				"for chopped \"StripOffsets\" array");
 	if (newcounts == NULL || newoffsets == NULL) {
 		/*
@@ -5562,18 +5560,18 @@ ChopUpSingleUncompressedStrip(TIFF* tif)
 	 * Fill the strip information arrays with new bytecounts and offsets
 	 * that reflect the broken-up format.
 	 */
-	for (strip = 0; strip < nstrips32; strip++) {
+	for (strip = 0; strip < nstrips; strip++) {
 		if (stripbytes > bytecount)
 			stripbytes = bytecount;
 		newcounts[strip] = stripbytes;
-		newoffsets[strip] = offset;
+		newoffsets[strip] = stripbytes ? offset : 0;
 		offset += stripbytes;
 		bytecount -= stripbytes;
 	}
 	/*
 	 * Replace old single strip info with multi-strip info.
 	 */
-	td->td_stripsperimage = td->td_nstrips = nstrips32;
+	td->td_stripsperimage = td->td_nstrips = nstrips;
 	TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP, rowsperstrip);
 
 	_TIFFfree(td->td_stripbytecount);

programming_language: SQL
filename: tif_strip.c
change_type: ModificationType.MODIFY
diff: @@ -63,15 +63,6 @@ TIFFNumberOfStrips(TIFF* tif)
 	TIFFDirectory *td = &tif->tif_dir;
 	uint32 nstrips;
 
-    /* If the value was already computed and store in td_nstrips, then return it,
-       since ChopUpSingleUncompressedStrip might have altered and resized the
-       since the td_stripbytecount and td_stripoffset arrays to the new value
-       after the initial affectation of td_nstrips = TIFFNumberOfStrips() in
-       tif_dirread.c ~line 3612.
-       See http://bugzilla.maptools.org/show_bug.cgi?id=2587 */
-    if( td->td_nstrips )
-        return td->td_nstrips;
-
 	nstrips = (td->td_rowsperstrip == (uint32) -1 ? 1 :
 	     TIFFhowmany_32(td->td_imagelength, td->td_rowsperstrip));
 	if (td->td_planarconfig == PLANARCONFIG_SEPARATE)

programming_language: C