CVSS: 7.8EPSS: 0%CPEs: 1EXPL: 0CVE-2019-17190
https://notcve.org/view.php?id=CVE-2019-17190
A Local Privilege Escalation issue was discovered in Avast Secure Browser 76.0.1659.101. The vulnerability is due to an insecure ACL set by the AvastBrowserUpdate.exe (which is running as NT AUTHORITY\SYSTEM) when AvastSecureBrowser.exe checks for new updates. When the update check is triggered, the elevated process cleans the ACL of the Update.ini file in %PROGRAMDATA%\Avast Software\Browser\Update\ and sets all privileges to group Everyone. Because any low-privileged user can create, delete, or modify the Update.ini file stored in this location, an attacker with low privileges can create a hard link named Update.ini in this folder, and make it point to a file writable by NT AUTHORITY\SYSTEM. Once AvastBrowserUpdate.exe is triggered by the update check functionality, the DACL is set to a misconfigured value on the crafted Update.ini and, consequently, to the target file that was previously not writable by the low-privileged attacker. • http://packetstormsecurity.com/files/156844/Avast-Secure-Browser-76.0.1659.101-Local-Privilege-Escalation.html http://seclists.org/fulldisclosure/2020/Mar/25 https://www.avast.com/bug-bounty-credits/en/a-tribute-to-our-security-research-community • CWE-863: Incorrect Authorization •
CVSS: 6.1EPSS: 0%CPEs: 3EXPL: 1CVE-2019-18893
https://notcve.org/view.php?id=CVE-2019-18893
XSS in the Video Downloader component before 1.5 of Avast Secure Browser 77.1.1831.91 and AVG Secure Browser 77.0.1790.77 allows websites to execute their code in the context of this component. While Video Downloader is technically a browser extension, it is granted a very wide set of privileges and can for example access cookies and browsing history, spy on the user while they are surfing the web, and alter their surfing experience in almost arbitrary ways. Una vulnerabilidad de tipo XSS en el componente Video Downloader versiones anteriores a la versión 1.5 del Avast Secure Browser versión 77.1.1831.91 y AVG Secure Browser versión 77.0.1790.77, permite a los sitios web ejecutar su código en el contexto de este componente. Aunque Video Downloader es técnicamente una extensión del navegador, se le otorga un rango muy amplio de privilegios y puede, por ejemplo, acceder a cookies y al historial de navegación, espiar al usuario mientras navega en la web y alterar su experiencia de navegación en modos casi arbitrarios. • https://palant.de/2020/01/13/pwning-avast-secure-browser-for-fun-and-profit • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') •