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<base href="https://bugs.freedesktop.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Reading outside bounds at Functions.cc:218"
href="https://bugs.freedesktop.org/show_bug.cgi?id=101501">101501</a>
</td>
</tr>
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<th>Summary</th>
<td>Reading outside bounds at Functions.cc:218
</td>
</tr>
<tr>
<th>Product</th>
<td>poppler
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>All
</td>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
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<th>Component</th>
<td>general
</td>
</tr>
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<th>Assignee</th>
<td>poppler-bugs@lists.freedesktop.org
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<th>Reporter</th>
<td>foca@salesforce.com
</td>
</tr></table>
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<div>
<pre>Created <span class=""><a href="attachment.cgi?id=132065" name="attach_132065" title="Proof of concept">attachment 132065</a> <a href="attachment.cgi?id=132065&action=edit" title="Proof of concept">[details]</a></span>
Proof of concept
There is a bug reading outside bounds at Functions.cc:218
212 }
213
214 void IdentityFunction::transform(double *in, double *out) {
215 int i;
216
217 for (i = 0; i < funcMaxOutputs; ++i) {
218 out[i] = in[i];
219 }
220 }
funcMacOutputs is defined in Functions.h:
#define funcMaxOutputs 32
Parsing the PoC.pdf, this function is called from GfxFunctionShading::getColor:
3957 void GfxFunctionShading::getColor(double x, double y, GfxColor *color) {
3958 double in[2], out[gfxColorMaxComps];
3959 int i;
3960
3961 // NB: there can be one function with n outputs or n functions with
3962 // one output each (where n = number of color components)
3963 for (i = 0; i < gfxColorMaxComps; ++i) {
3964 out[i] = 0;
3965 }
3966 in[0] = x;
3967 in[1] = y;
3968 for (i = 0; i < nFuncs; ++i) {
3969 funcs[i]->transform(in, &out[i]);
3970 }
3971 for (i = 0; i < gfxColorMaxComps; ++i) {
3972 color->c[i] = dblToCol(out[i]);
3973 }
3974 }
Where the variable in has only 2 elements, instead of the 32 read at
IdentityFunction::transform. So 30 elements are read after the in.
This could be fixed increasing the number of elements for the variable in:
3958 double in[gfxColorMaxComps], out[gfxColorMaxComps];
PoC is attached.
This vulnerability has been found by Offensive Research at Salesforce.com:
Alberto Garcia (@algillera), Francisco Oca (@francisco_oca) & Suleman Ali
(@Salbei_)</pre>
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