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Fencer Intel
critical 9.8

CVE-2020-29390 in the critical feed json

Zeroshell 3.9.3 contains a command injection vulnerability in the /cgi-bin/kerbynet StartSessionSubmit parameter that could allow an unauth…

published 5y ago modified 4mo ago also EUVD-2020-21763

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
39.6%
EPSS 39.6% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known, plus a Nuclei check

Summary

Zeroshell 3.9.3 contains a command injection vulnerability in the /cgi-bin/kerbynet StartSessionSubmit parameter that could allow an unauthenticated attacker to execute a system command by using shell metacharacters and the %0a character.

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Exploit prediction

39.57% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • Nuclei template Zeroshell 3.9.3 - Command Injection nuclei detection template
  • blog.quake.so https://blog.quake.so/post/zeroshell_linux_router_rce/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

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

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.