CVE-2021-43855
CVE-2021-43855 — Stored XSS via SVG in Requarks/wiki
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.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
1%
chance of exploitation in 30 days
CVSS base
8.2
HIGH
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 8.2 | CVSS 3.1 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-79
References
3 on the record
- github.com/Requarks/wiki/releases/tag/2.5.264
x_refsource_MISC
- github.com/Requarks/wiki/security/advisories/GHSA-4893-pj5w-3hq9
x_refsource_CONFIRM
- github.com/Requarks/wiki/commit/57b56d3a5b9c00358814e76f3ee5b4bb353ad62f
x_refsource_MISC
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.