PT-2020-17155 · Zeroshell · Zeroshell

CVE-2020-29390 · Published 2020-11-30 · Updated 2025-07-16

Positive Technologies (AI Summary)

CVSS v2.0

10

Critical

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Zeroshell version 3.9.3

Description The issue allows an unauthenticated attacker to execute a system command by using shell metacharacters and the %0a character in the /cgi-bin/kerbynet API endpoint, specifically through the StartSessionSubmit parameter.

Recommendations For Zeroshell version 3.9.3, consider disabling access to the /cgi-bin/kerbynet API endpoint or restricting the use of the StartSessionSubmit parameter until a patch is available. Avoid using shell metacharacters and the %0a character in the StartSessionSubmit parameter to minimize the risk of exploitation.

Exploit

Fix

OS Command Injection

Weakness Enumeration

CWE-78

Related Identifiers

CVE-2020-29390

Affected Products

Zeroshell

References · 7

• 🔥 https://blog.quake.so/post/zeroshell_linux_router_rce · Exploit
• https://osv.dev/vulnerability/CVE-2020-29390 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-29390 · Security Note
• https://t.me/cibsecurity/16938 · Telegram Post
• https://t.me/cvenotify/6557 · Telegram Post
• https://twitter.com/pdnuclei_bot/status/1945453381851754782 · Twitter Post
• https://twitter.com/pdnuclei/status/1945407290368016707 · Twitter Post