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Fencer Vulns
medium 5.3

CVE-2021-28963 json

Shibboleth Service Provider before 3.2.1 allows content injection because template generation uses attacker-controlled parameters.

published 2021-03-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-15612

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

Shibboleth Service Provider before 3.2.1 allows content injection because template generation uses attacker-controlled parameters.

Patch / fix

  • shibboleth service_provider 3.2.1
  • shibboleth-sp Debian 14, Debian 13, Debian 12 3.2.1+dfsg1-1

debian advisories DEBIAN-CVE-2021-28963

  • shibboleth-sp Ubuntu 20.04 LTS 3.0.4+dfsg1-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2021-28963

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

1.31% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

Sources

Fencer Vulns 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.