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Fencer Intel
medium 6.8

CVE-2021-32661 json

TechDocs object element script injection

published 5y ago modified 4mo ago also GHSA-gg96-f8wr-p89f , EUVD-2021-1324

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

Backstage is an open platform for building developer portals. In versions of Backstage's Techdocs Plugin (`@backstage/plugin-techdocs`) prior to 0.9.5, a malicious internal actor can potentially upload documentation content with malicious scripts by embedding the script within an `object` element. This may give access to sensitive data when other users visit that same documentation page. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the `0.9.5` release of `@backstage/plugin-techdocs`.

Patch / fix

  • npm @backstage/plugin-techdocs 0.9.5
  • linuxfoundation @backstage/plugin-techdocs 0.9.5

Is CVE-2021-32661 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

1.21% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
NVD 2.0 4.9 AV:N/AC:M/Au:S/C:P/I:P/A:N
GitHub 3.1 6.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
npm @backstage/plugin-techdocs
<0.9.5
0.9.5

Affected products

  • backstage backstage

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command
  • CWE-434 Unrestricted Upload of File with Dangerous Type

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.