CVE-2025-4084Network attack vector

Local code execution via unescaped cURL metacharacters

Published Apr 29, 2025 · Updated Apr 13, 2026

Improper output escaping in Mozilla Firefox ESR 115 and 128 allows attackers to inject shell commands into generated Windows cURL commands. The Copy as cURL feature fails to escape shell metacharacters, including ampersands, when converting request data into command text; execution requires a user to copy and run that text in a Windows shell. The CNA lists Firefox ESR before 115.23 and before 128.10, plus Thunderbird before 128.10, although Mozilla's description limits affected behavior to Firefox on Windows.

CVSS severity5.7
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper output escaping in Mozilla Firefox ESR 115 and 128 allows attackers to inject shell commands into generated Windows cURL commands. The Copy as cURL feature fails to escape shell metacharacters, including ampersands, when converting request data into command text; execution requires a user to copy and run that text in a Windows shell. The CNA lists Firefox ESR before 115.23 and before 128.10, plus Thunderbird before 128.10, although Mozilla's description limits affected behavior to Firefox on Windows.

The record

CVE
CVE-2025-4084
Published
Apr 29, 2025
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-116, T1059.003, T1204
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.7CISACVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output
T1059.003Command and Scripting Interpreter: Windows Command Shell
T1204User Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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