CVE-2021-43855
What it is
Wiki.js is a wiki app built on node.js. Wiki.js 2.5.263 and earlier is vulnerable to stored cross-site scripting through a SVG file upload made via a custom request with a fake MIME type. By creating a crafted SVG file, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the SVG is viewed directly by other users. Scripts do not execute when loaded inside a page via normal `<img>` tags. The malicious SVG can only be uploaded by crafting a custom request to the server with a fake MIME type. A patch in version 2.5.264 fixes this vulnerability by adding an additional file extension verification check to the optional (enabled by default) SVG sanitization step to all file uploads that match the SVG mime type. As a workaround, disable file upload for all non-trusted users.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure.
- Exploit odds
- 0.9% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.9% in the next 30 days (EPSS).
- Severity: 8.2 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.9% · EPSS, next 30 days
- Weakness
- CWE-79 · Cross-site scripting
- Record status
- Modified
Affected
- Requarks wiki.js < 2.5.264
Attack profile CVSS 3.1 · 8.2
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-43855.md and follow it. Check whether this project is affected by CVE-2021-43855. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/Requarks/wiki/commit/57b56d3a5b9c00358814e76f3ee5b4bb353ad62f
- https://github.com/Requarks/wiki/releases/tag/2.5.264
- https://github.com/Requarks/wiki/security/advisories/GHSA-4893-pj5w-3hq9
- https://github.com/Requarks/wiki/commit/57b56d3a5b9c00358814e76f3ee5b4bb353ad62f
- https://github.com/Requarks/wiki/releases/tag/2.5.264
- https://github.com/Requarks/wiki/security/advisories/GHSA-4893-pj5w-3hq9
References
- https://github.com/Requarks/wiki/commit/57b56d3a5b9c00358814e76f3ee5b4bb353ad62f
- https://github.com/Requarks/wiki/releases/tag/2.5.264
- https://github.com/Requarks/wiki/security/advisories/GHSA-4893-pj5w-3hq9
- https://github.com/Requarks/wiki/commit/57b56d3a5b9c00358814e76f3ee5b4bb353ad62f
- https://github.com/Requarks/wiki/releases/tag/2.5.264
- https://github.com/Requarks/wiki/security/advisories/GHSA-4893-pj5w-3hq9