Input validation error in QPDF - CVE-2018-18020
Published: October 6, 2018 / Updated: August 8, 2020
Vulnerability identifier: #VU36557
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2018-18020
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote non-authenticated attacker to perform service disruption.
In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild have recursive calls for a long time, which allows remote attackers to cause a denial of service via a crafted PDF file.
Affected software
QPDF
Ubuntu
qpdf (Ubuntu package)
libqpdf21 (Ubuntu package)
libqpdf26 (Ubuntu package)
Ubuntu
qpdf (Ubuntu package)
libqpdf21 (Ubuntu package)
libqpdf26 (Ubuntu package)
How to mitigate CVE-2018-18020
Install update from vendor's website.
qpdf (Ubuntu package) - addressed in versions 8.0.2-3ubuntu0.1, 8.0.23~16.04.1+esm1, 9.1.1-1ubuntu0.1
libqpdf21 (Ubuntu package) - addressed in versions 8.0.2-3ubuntu0.1, 8.0.23~16.04.1+esm1
libqpdf26 (Ubuntu package) - update to 9.1.1-1ubuntu0.1
libqpdf21 (Ubuntu package) - addressed in versions 8.0.2-3ubuntu0.1, 8.0.23~16.04.1+esm1
libqpdf26 (Ubuntu package) - update to 9.1.1-1ubuntu0.1