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Fencer Vulns
high 7.5

CVE-2021-28117 json

libdiscover/backends/KNSBackend/KNSResource.cpp in KDE Discover before 5.21.3 automatically creates links to potentially dangerous URLs (th…

published 2021-03-20 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-14818

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

libdiscover/backends/KNSBackend/KNSResource.cpp in KDE Discover before 5.21.3 automatically creates links to potentially dangerous URLs (that are neither https:// nor http://) based on the content of the store.kde.org web site. (5.18.7 is also a fixed version.)

Patch / fix

  • kde discover 5.21.3
  • plasma-discover Debian 14, Debian 13, Debian 12 5.20.5-3

debian advisories DEBIAN-CVE-2021-28117

  • discover Alpine 3.13 5.20.5-r1
  • discover Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 5.21.3-r0

alpine advisories ALPINE-CVE-2021-28117

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • discover Arch Linux 5.21.3-1

arch linux advisories AVG-1672

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-28117 updated cvss 5.3

plasma-discover: missing URI scheme validation

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

1.56% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

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.