CVE-2017-7761
This vulnerability affects Firefox ESR < 52.2 and Firefox < 54.
Does this matter?
Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.0
- 5.5 MEDIUMCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.30% probability · 23th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-276
- Affected
- mozilla/firefox
- Source
- security@mozilla.org
EPSS 0.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/99057Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1038689Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1215648Issue Tracking, Vendor Advisory
- https://sourceforge.net/p/nsis/bugs/1125/Issue Tracking, Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-15/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-16/Vendor Advisory
- http://www.securityfocus.com/bid/99057Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1038689Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1215648Issue Tracking, Vendor Advisory
- https://sourceforge.net/p/nsis/bugs/1125/Issue Tracking, Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-15/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-16/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.