SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-15677

By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to show the original site (the one suffering from the open redirect) rather than the site the file was actually…

MEDIUM 6.1EPSS 1.66%

Does this matter?

Lower severity and a low EPSS score (1.66%). Track it; it rarely justifies an emergency change on its own.

Description

By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to show the original site (the one suffering from the open redirect) rather than the site the file was actually downloaded from. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

CVSS 3.1
6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS
1.66% probability · 76th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-601
Affected
mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird · debian/debian linux · opensuse/leap
Source
security@mozilla.org
EPSS trend
0%3%5%26 October 2026: 1.66%26 October 202626 October 2026

EPSS 1.7% since 26 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

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