Vigil@nce - Apache POI: external XML entity injection
February 2018 by Vigil@nce
This bulletin was written by Vigil@nce : https://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
An attacker can transmit malicious XML data to Apache POI, in order to read a file, scan sites, or trigger a denial of service.
Impacted products: QRadar SIEM.
Creation date: 19/12/2017.
DESCRIPTION OF THE VULNERABILITY
XML data can contain external entities (DTD):
A program which reads these XML data can replace these entities by
data coming from the indicated file. When the program uses XML
data coming from an untrusted source, this behavior leads to:
content disclosure from files of the server
private web site scan
a denial of service by opening a blocking file
This feature must be disabled to process XML data coming from an untrusted source.
However, the Apache POI parser allows external entities.
An attacker can therefore transmit malicious XML data to Apache POI, in order to read a file, scan sites, or trigger a denial of service.
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