CVE-2017-7796 Path traversal in Firefox
A local attacker can exploit the Windows updater's log deletion logic to delete arbitrary files named update.log, potentially aiding other exploits.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-7796?
CVE-2017-7796 is a medium-severity path traversal vulnerability in Mozilla Firefox, published on 11 Jun 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
On Windows systems, the logger run by the Windows updater deletes the file "update.log" before it runs in order to write a new log of that name. The path to this file is supplied at the command line to the updater and could be used in concert with another local exploit to delete a different file named "update.log" instead of the one intended. Note: This attack only affects Windows operating systems. Other operating systems are not affected. This vulnerability affects Firefox < 55.
Weakness: CWE-20
Which versions are affected by CVE-2017-7796?
It affects 1 product.
Products include Mozilla Firefox.
How do I fix CVE-2017-7796?
Upgrade to a fixed version.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2017-7796 being exploited?
There is no known exploitation of CVE-2017-7796 in the wild and no public exploit code.
Other vulnerabilities in Mozilla Firefox
Sources
Also known as GHSA-vqcv-9479-342r.