<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - NULL pointer dereference in GooString.cc:867"
href="https://bugs.freedesktop.org/show_bug.cgi?id=101523">101523</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>NULL pointer dereference in GooString.cc:867
</td>
</tr>
<tr>
<th>Product</th>
<td>poppler
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>general
</td>
</tr>
<tr>
<th>Assignee</th>
<td>poppler-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>foca@salesforce.com
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=132093" name="attach_132093" title="Proof of concept">attachment 132093</a> <a href="attachment.cgi?id=132093&action=edit" title="Proof of concept">[details]</a></span>
Proof of concept
There is a NULL dereference parsing the attached PoC.pdf.
The NULL dereference happens in GooString.cc:867
863 int GooString::cmp(const char *sA) const {
864 int n1, i, x;
865 const char *p1, *p2;
866
867 n1 = length;
"this" is NULL so this->n1 at 867 generates the SIGSEGV. The reason this is
null is because the previous function GfxCIDFont::getCodeToGIDMap in
GfxFont.cc:2375 calls a method of a NULL object:
2373 *mapsizep = 0;
2374 if (!ctu) return NULL;
2375 if (getCollection()->cmp("Adobe-Identity") == 0) return NULL;
2376 if (getEmbeddedFontID(&embID)) {
Parsing the PoC.pdf getCollection() returns NULL but the method cmp is called.
The solution should be check for the return value before call cmp:
2375 if (getCollection() == NULL || getCollection()->cmp("Adobe-Identity")
== 0) return NULL;
PoC attached. To reproduce the bug use:
pdftocairo -svg PoC.pdf
This vulnerability has been found by Offensive Research at Salesforce.com:
Alberto Garcia (@algillera), Francisco Oca (@francisco_oca) & Suleman Ali
(@Salbei_)</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>