SecuriTricks - CVE-2024-45800

Description

Snappymail is an open source web-based email client. SnappyMail uses the `cleanHtml()` function to cleanup HTML and CSS in emails. Research discovered that the function has a few bugs which cause an mXSS exploit. Because the function allowed too many (invalid) HTML elements, it was possible (with incorrect markup) to trick the browser to "fix" the broken markup into valid markup. As a result a motivated attacker may be able to inject javascript. However, due to the default Content Security Policy the impact of the exploit is minimal. It could be possible to create an attack which leaks some data when loading images through the proxy. This way it might be possible to use the proxy to attack the local system, like with `http://localhost:5000/leak`. Another attack could be to load a JavaScript attachment of the email. This is very tricky as the email must link to every possible UID as each email has a unique UID which has a value between 1 and 18446744073709551615 **v2.38.0** and up now remove unsupported HTML elements which mitigates the issue. Users are advised to upgrade. Older versions can install an extension named "Security mXSS" as a mitigation. This will be available at the administration area at `/?admin#/packages`. **NOTE:** this extension can not "fix" malicious code in encrypted messages or (html) attachments as it can't manipulate the JavaScript code for this. It only protects normal message HTML.

Product(s) Impacted

Product	Versions
Snappymail	2.38.0 and above

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

References

https://github.com/the-djmaze/snappymail/blob/master/dev/Common/Html.js

https://github.com/the-djmaze/snappymail/commit/cfbc47488a6b2e2ae4be484f501ee1a3485f542e

https://github.com/the-djmaze/snappymail/security/advisories/GHSA-2rq7-79vp-ffxm

CVSS Score

5.0 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: HIGH
Privileges Required: NONE
Scope: UNCHANGED
Confidentiality Impact: LOW
Integrity Impact: LOW
Availability Impact: LOW

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

View Vector String

Timeline

Published: Sept. 16, 2024, 8:15 p.m.
Last Modified: Sept. 20, 2024, 12:31 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

security-advisories@github.com

CVE-2024-45800