EXPLIoT CloudFuzz


Through sharp, technical and insightful analysis, the Payatu Team is constantly on the lookout for vulnerabilities and threats. This section exhibits a few of our findings.


Out of Bounds Write Heap Buffer Google Chrome PDFium


Improper Restriction of Operations within the Bounds of a Memory Buffer Vulnerability

Vulnerability Description

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Google Chrome. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within Google Chrome’s PDF accessibility code. GetTextRunInfo scans until it finds the start of the next text run, then increments the character index by 1 in order to scan to the end of the text run. That was resulting in a buffer overrun if the first scan reached the end of the array of characters without finding a non-whitespace character. An attacker can leverage this vulnerability to execute code under the context of the current process.





  • Google Chrome 54.0.2840.99 and prior

Disclosure Timeline

  1. 25 November 2016 – Reported to vendor
  2. 9 March 2017 – Coordinated public release of advisory


Ashfaq Ansari – Project Srishti

Vendor Advisory

Code Review