Critical Remote Code Execution
vulnerability has been discovered in the most popular and most feature-rich PDF
reader, Adobe Acrobat Reader DC.
The vulnerability has the power
to perform a stack-based buffer overflow all the executing the orbitary code
when users open the vulnerable Adobe document.This Critical RCE
vulnerability affected the version of Adobe Acrobat Reader DC 2018.009.20044
and Below.
Albeit the reason anticipated as to why Adobe was targeted
is quite simple to fathom it has a major user base, is the most prevalent and
most feature-rich PDF reader and is usually a default PDF reader on systems and
incorporates into web browsers as a plugin for rendering PDFs.
This most likely makes it substantially easier for an attacker to send the specific
crafted malicious document by means of an email or deceiving a user into
visiting a malicious web page and influence the user execute the malicious
document and trigger this vulnerability.Considering the Remote Code Execution Working Flow where the
application bolsters the embedded JavaScript within the Adobe document and enables
it to work as PDF form.
This could be hands down mishandled by an attacker utilizing
the vulnerability for an additional attack surface.
When parsing a PDF
file with overly large Document ID field specified in the trailer, according to
Aleksandar Nikolic of Cisco Talos, it
is parsed correctly initially, but when it’s referenced in JavaScript, a
stack-based buffer overflow can occur when encoding the bytes to a hex string.
Here is a sample document ID:
In this case, Cisco Providing a simple JavaScript to trigger
this critical Remote code execution vulnerability.
“the specified part
of document ID field is hex-decoded into a sequence of bytes. When a this.docID
is dereferenced in JavaScript, this byte sequence is encoded back into an ascii
hex string again function at EScript+0x9e7c0”
Nonetheless this vulnerability has been reported to Adobe,
patch has been made and released an update on 2018 -02-13 with CVE-2018-4901.
