Vulnerability in Mozilla Firefox

CVE-2020-15658

The code for downloading files did not properly take care of special characters, which led to an attacker being able to cut off the file ending at an earlier position, leading to a different file type being downloaded than shown in the dialog. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

EPSS: 0.012 (65.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-15658?
CVE-2020-15658 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 6.5/10. Published 2020-08-10.
How severe is CVE-2020-15658?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2020-15658 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.