CVE-2021-23985

MEDIUM
6.5
CVSS Score
Published: March 31, 2021 at 01:41 PM UTC
Updated: June 17, 2026 at 03:39 AM UTC
1 product affected across 1 vendorFirefox

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Severity
MEDIUM6.5
Exploit prediction
EPSS 2%

Description

If an attacker is able to alter specific about:config values (for example malware running on the user's computer), the Devtools remote debugging feature could have been enabled in a way that was unnoticable to the user. This would have allowed a remote attacker (able to make a direct network connection to the victim) to monitor the user's browsing activity and (plaintext) network traffic. This was addressed by providing a visual cue when Devtools has an open network socket. This vulnerability affects Firefox < 87.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 87
Affected range stops below 87, so it looks safe — our inference, not a vendor statement
Affected range stops below 87.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1659129

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-Other

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