CVE-2017-7761 Privilege escalation in Firefox
Local attackers can delete protected files via junction attacks in the Mozilla Maintenance Service, leading to privilege escalation.
- 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-2017-7761?
CVE-2017-7761 is a medium-severity 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
The Mozilla Maintenance Service "helper.exe" application creates a temporary directory writable by non-privileged users. When this is combined with creation of a junction (a form of symbolic link), protected files in the target directory of the junction can be deleted by the Mozilla Maintenance Service, which has privileged access. Note: This attack requires local system access and only affects Windows. Other operating systems are not affected. This vulnerability affects Firefox ESR < 52.2 and Firefox < 54.
Weakness: CWE-276
Which versions are affected by CVE-2017-7761?
It affects 1 product.
Products include Mozilla Firefox.
How do I fix CVE-2017-7761?
Upgrade to a fixed version.
Is CVE-2017-7761 being exploited?
There is no known exploitation of CVE-2017-7761 in the wild and no public exploit code.
Other vulnerabilities in Mozilla Firefox
Sources
Also known as GHSA-mcm9-29wj-77v9.