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Fencer Vulns
high 8.8

CVE-2021-3317 in the critical feed json

KLog Server through 2.4.1 allows authenticated command injection.

published 2021-01-26 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26648

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
41.4%
EPSS 41.4% chance of exploitation in 30 days, percentile 98%
public exploits
1
Exploit-DB

Summary

KLog Server through 2.4.1 allows authenticated command injection. async.php calls shell_exec() on the original value of the source parameter.

Timeline

  1. Published
  2. First public exploit (EDB-49511)

Exploit prediction

41.39% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-49511 Klog Server 2.4.1 - Command Injection (Authenticated) webapps, 2021-02-01
  • docs.unsafe-inline.com https://docs.unsafe-inline.com/0day/klog-server-authenticated-command-injection referenced PoC, tagged "exploit" by a source, unverified
  • packetstormsecurity.com http://packetstormsecurity.com/files/161208/Klog-Server-2.4.1-Command-Injection.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

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.