Announced 17 September 2020

Score: High

Several security issues, 8 rated as high, affect the Firefox ESR web browser on:

  • IGEL OS 11
  • IGEL OS 10
  • IGEL Linux 5


It has been found that manipulating individual parts of a URL object could have caused an out-of-bounds read, leaking process memory to malicious JavaScript (CVE-2020-12418). Apart from that, by observing the stack trace for JavaScript errors in web workers, it was possible to leak the result of a cross-origin redirect (CVE-2020-15652. The WebRTC data channel could leak internal memory addresses to a peer, enabling them to bypass ASLR (CVE-2020-6514).
Another vulnerability allowed a malicious webpage to prompt the user to install an extension. Combined with user confusion, this could result in an unintended or malicious extension being installed (CVE-2020-15664).
Finally, a number of memory management bugs have been discovered (CVE-2020-12419, CVE-2020-12420, CVE-2020-15659, CVE-2020-15669).

Update Instructions

  • IGEL OS 11: Update to IGEL OS 11.04.130 or newer.
  • IGEL OS 10: An updated version is upcoming. When it is available, this document will be updated.
  • IGEL Linux 5: This version does not have the space required for the Firefox ESR update. IGEL recommends removing the web browser feature if possible:


Mozilla Foundation Security Advisory 2020-25:

Mozilla Foundation Security Advisory 2020-31:

Mozilla Foundation Security Advisory 2020-37: