// For flags

CVE-2025-1936

firefox: Adding %00 and a fake extension to a jar: URL changed the interpretation of the contents

Severity Score

7.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

jar: URLs retrieve local file content packaged in a ZIP archive. The null and everything after it was ignored when retrieving the content from the archive, but the fake extension after the null was used to determine the type of content. This could have been used to hide code in a web extension disguised as something else like an image. This vulnerability affects Firefox < 136 and Firefox ESR < 128.8.

jar: URLs retrieve local file content packaged in a ZIP archive. The null and everything after it was ignored when retrieving the content from the archive, but the fake extension after the null was used to determine the type of content. This could have been used to hide code in a web extension disguised as something else like an image. This vulnerability affects Firefox < 136, Firefox ESR < 128.8, Thunderbird < 136, and Thunderbird < 128.8.

Multiple security issues have been found in the Mozilla Firefox web browser, which could potentially result in the execution of arbitrary code.

*Credits: Surya Dev Singh
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
None
Automatable
Yes
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-03-04 CVE Reserved
  • 2025-03-04 CVE Published
  • 2025-03-26 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-158: Improper Neutralization of Null Byte or NUL Character
  • CWE-754: Improper Check for Unusual or Exceptional Conditions
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mozilla
Search vendor "Mozilla"
 Firefox
Search vendor "Mozilla" for product "Firefox"
*-
Affected
Mozilla
Search vendor "Mozilla"
 Firefox Esr
Search vendor "Mozilla" for product "Firefox Esr"
*-
Affected
Mozilla
Search vendor "Mozilla"
 Thunderbird
Search vendor "Mozilla" for product "Thunderbird"
*-
Affected
Slackware
Search vendor "Slackware"
 Slackware Linux
Search vendor "Slackware" for product "Slackware Linux"
*-
Affected