Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2025-6435— Save as in Devtools could download files without sanitizing the extension

Quick assessment

Affected
Mozilla Firefox
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Mozilla Firefox是美国Mozilla基金会的一款开源Web浏览器。 Firefox 140之前版本存在安全漏洞，该漏洞源于Devtools网络标签保存响应时未使用.download扩展名，可能导致用户误运行恶意可执行文件。

AI Predicted 5.5 Difficulty: Moderate EPSS 0.39% · P32

Possible ATT&CK Techniques 1 AI

T1059 · Command and Scripting Interpreter
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2025-6435

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Save as in Devtools could download files without sanitizing the extension
Source: CVE Program / CVE List V5
Vulnerability Description
If a user saved a response from the Network tab in Devtools using the Save As context menu option, that file may not have been saved with the `.download` file extension. This could have led to the user inadvertently running a malicious executable. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Mozilla Firefox 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Mozilla Firefox是美国Mozilla基金会的一款开源Web浏览器。 Firefox 140之前版本存在安全漏洞，该漏洞源于Devtools网络标签保存响应时未使用.download扩展名，可能导致用户误运行恶意可执行文件。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Mozilla Firefox 140 ~ * -
Mozilla Thunderbird 140 ~ * -

II. Public POCs for CVE-2025-6435

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2025-6435

请登录查看更多情报信息。

Vendor Advisories for CVE-2025-6435 (2)

Same Patch Batch · Mozilla · 2025-06-24 · 13 CVEs total

CVE-2025-6436 Memory safety bugs fixed in Firefox 140 and Thunderbird 140
CVE-2025-6432 DNS Requests leaked outside of a configured SOCKS proxy
CVE-2025-6434 HTTPS-Only exception screen lacked anti-clickjacking delay
CVE-2025-6433 WebAuthn would allow a user to sign a challenge on a webpage with an invalid TLS certifica
CVE-2025-6431 The prompt in Firefox for Android that asks before opening a link in an external applicati
CVE-2025-6428 Firefox for Android opened URLs specified in a link querystring parameter
CVE-2025-6429 Incorrect parsing of URLs could have allowed embedding of youtube.com
CVE-2025-6430 Content-Disposition header ignored when a file is included in an embed or object tag
CVE-2025-6427 connect-src Content Security Policy restriction could be bypassed
CVE-2025-6426 No warning when opening executable terminal files on macOS
CVE-2025-6424 Use-after-free in FontFaceSet
CVE-2025-6425 The WebCompat WebExtension shipped with Firefox exposed a persistent UUID

IV. Related Vulnerabilities

Same product: Firefox
Same vendor: Mozilla

V. Comments for CVE-2025-6435

No comments yet

Leave a comment