[UNIX] Link Grammar "separate_sentence()" Buffer Overflow

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Link Grammar "separate_sentence()" Buffer Overflow
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SUMMARY

The <http://www.link.cs.cmu.edu/link/> Link Grammar Parser is "a
syntactic parser of English, based on link grammar, an original theory of
English syntax. Given a sentence, the system assigns to it a syntactic
structure, which consists of a set of labeled links connecting pairs of
words. The parser also produces a "constituent" representation of a
sentence (showing noun phrases, verb phrases, etc.)" Secunia Research has
discovered a vulnerability in Link Grammar, which can be exploited by
malicious people to compromise an application using the affected code.

DETAILS

Vulnerable Systems:
* Link Grammar version 4.1b

The vulnerability is caused due to a boundary error within the
"separate_word()" function in tokenize.c when processing overly long words
(over 61 bytes). This can be exploited to cause a stack-based buffer
overflow via a specially crafted sentence passed to the
"separate_sentence()" function.

Successful exploitation allows execution of arbitrary code.

Time Table:
23/10/2007 - Vendor notified.
07/11/2007 - Public disclosure.

CVE Information:
<http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5395>
CVE-2007-5395

ADDITIONAL INFORMATION

The information has been provided by Secunia Research.
The original article can be found at:
<http://secunia.com/secunia_research/2007-78/>

http://secunia.com/secunia_research/2007-78/

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