SuSE reported a buffer overflow in FoFiType1::parse affecting older xpdf versions. Code snippets from fofi/FoFiType1.cc:

133 void FoFiType1::parse() { ... 163 line = getNextLine(line); 164 for (j = 0; j < 300 && line; ++j) { 165 line1 = getNextLine(line); 166 if ((n = line1 - line) > 255) { 167 n = 255; 168 } 169 strncpy(buf, line, n);

getNextLine can, however, return NULL:

117 char FoFiType1::getNextLine(char line) { 118 while (line < (char )file + len && line != '\x0a' && line != '\x0d') { 119 ++line; 120 } 121 if (line < (char )file + len && line == '\x0d') { 122 ++line; 123 } 124 if (line < (char )file + len && line == '\x0a') { 125 ++line; 126 } 127 if (line >= (char )file + len) { 128 return NULL; 129 }

Therefore, (line1 - line) is not defined / results in negative value n. That value is later passed to strncpy, causing overflow of buf buffer.

Adam Zabrocki reported flaws in xpdf's Splash::drawImage function related to buffer memory allocations:

2220 // allocate pixel buffers 2221 colorBuf = (SplashColorPtr)gmalloc((yp + 1) w nComps); 2222 if (srcAlpha) { 2223 alphaBuf = (Guchar )gmalloc((yp + 1) w); 2224 } else { 2225 alphaBuf = NULL; 2226 }

Values used to compute argument passed to gmalloc come from input PDF file. Properly chosen values will cause gmalloc to return NULL or buffer of insufficient size, leading to NULL pointer dereference or heap buffer overflow later.

Affected Splash output device is not available in xpdf 2.x versions and earlier. It is also not used in xpdf embedded in CUPS or tetex.

This was already fixed in poppler as part of preventive gmalloc -> gmallocn changes: http://cgit.freedesktop.org/poppler/poppler/commit/?id=9cf2325fb2

This fix is also present in the EL5 poppler packages.

Acknowledgements:

Red Hat would like to thank Adam Zabrocki for reporting this issue.

An integer overflow flaw exists in xpdf's ImageStream::ImageStream (Stream.cc) when calculating size of the imgLine buffer:

320 nVals = width nComps; 321 if (nBits == 1) { 322 imgLineSize = (nVals + 7) & ~7; 323 } else { 324 imgLineSize = nVals; 325 } 326 imgLine = (Guchar )gmallocn(imgLineSize, sizeof(Guchar));

width and nComps used go compute nVals value come from the input PDF file. Their multiplication may overflow / wrap, resulting in smaller imgLine buffer allocation than expected.

ImageStream always uses nVals as an upper bound when writing data into imgLine. Therefore, no buffer overflow occurs in ImageStream, but NULL pointer dereference may occur (gmallocn returns NULL when called with imgLineSize 0).

Pointer to imgLine is also returned out of ImageStream class instance from ImageStream::getLine() method. Callers of the method may later over-read allocated buffer, but no caller over-writing it was identified.

This code was introduced in xpdf in some early versions (exists in 0.9x), so is likely to appear in all applications embedding / forking xpdf.

Integer overflow in the ObjectStream::ObjectStream function in XRef.cc in Xpdf 3.x before 3.02pl4 and Poppler before 0.12.1, as used in GPdf, kdegraphics KPDF, CUPS pdftops, and teTeX, might allow remote attackers to execute arbitrary code via a crafted PDF document that triggers a heap-based buffer overflow.

Unspecified vulnerability in certain versions of xpdf after 3.00, as used in various products including (a) pdfkit.framework, (b) gpdf, (c) pdftohtml, and (d) libextractor, has unknown impact and user-assisted attack vectors, possibly involving errors in (1) gmem.c, (2) SplashXPathScanner.cc, (3) JBIG2Stream.cc, (4) JPXStream.cc, and/or (5) Stream.cc. NOTE: this description is based on Debian advisory DSA 979, which is based on changes that were made after other vulnerabilities such as CVE-2006-0301 and CVE-2005-3624 through CVE-2005-3628 were fixed. Some of these newer fixes appear to be security-relevant, although it is not clear if they fix specific issues or are defensive in nature.

The patch for integer overflow vulnerabilities in Xpdf 2.0 and 3.0 (CVE-2004-0888) is incomplete for 64-bit architectures on certain Linux distributions such as Red Hat, which could leave Xpdf users exposed to the original vulnerabilities.

Multiple integer overflows in xpdf 3.0, and other packages that use xpdf code such as CUPS, allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code, a different set of vulnerabilities than those identified by CVE-2004-0888.

Multiple integer overflows in xpdf 2.0 and 3.0, and other packages that use xpdf code such as CUPS, gpdf, and kdegraphics, allow remote attackers to cause a denial of service (crash) and possibly execute arbitrary code, a different set of vulnerabilities than those identified by CVE-2004-0889.