SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-7796

This vulnerability affects Firefox < 55.

MEDIUM 4.7EPSS 0.27%

Does this matter?

Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.0
4.7 MEDIUMCVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS
0.27% probability · 19th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-20
Affected
mozilla/firefox
Source
security@mozilla.org
EPSS trend
0%3%5%27 October 2026: 0.27%27 October 202627 October 2026

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.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.