Cyber Resilience

CVE-2021-23973

Medium

Published: 26 February 2021

Published
26 February 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS Score 0.0084 75.3th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23973 is a medium-severity Generation of Error Message Containing Sensitive Information (CWE-209) vulnerability in Debian Debian Linux. Its CVSS base score is 6.5 (Medium).

Operationally, ranked in the top 24.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted, and the content of that error may have revealed information about the resource. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and…

more

Firefox ESR < 78.8.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

mozilla
firefox
≤ 86.0
mozilla
firefox esr
≤ 78.8
mozilla
thunderbird
≤ 78.8
debian
debian linux
10.0, 9.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-209

Detects error messages that leak sensitive information as evidence of disclosure.

addresses: CWE-209

The control directly mitigates generation of error messages containing sensitive authentication details by requiring obscured feedback instead of verbose responses.

addresses: CWE-209

Misdirection allows generation of misleading error messages that withhold or falsify sensitive details.

addresses: CWE-209

Explicitly requires error messages to avoid including sensitive or exploitable details while still supporting corrective action.

addresses: CWE-209

Validation ensures error messages contain only expected, non-sensitive content and blocks leakage via verbose errors.

addresses: CWE-209

Fail-safe procedures can be defined to suppress or sanitize error output, reducing generation of messages that contain sensitive information.

References