Paramiko not properly checking authentication before processing other requests

CVE-2018-7750 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

transport.py in the SSH server implementation of Paramiko before 1.17.6, 1.18.x before 1.18.5, 2.0.x before 2.0.8, 2.1.x before 2.1.5, 2.2.x before 2.2.3, 2.3.x before 2.3.2, and 2.4.x before 2.4.1 does not properly check whether authentication is completed before processing other requests, as demonstrated by channel-open. A customized SSH client can simply skip the authentication step.

Basic information

Type
reviewed
Severity
critical
Advisory on GitHub
Open advisory ↗
Repository advisory
—
Source code
Browse source ↗
Published (advisory)
2018-07-12 20:29:30 UTC
Updated
2026-06-09 12:59:27 UTC
GitHub reviewed
2020-06-16 20:50:58 UTC
NVD published
2018-03-13

EPSS Score

Score Percentile
17.69% 95.25%

CVSS Scores

Base score Version Severity Vector
9.8 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
9.3 4.0 —
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

Type Value
GHSA GHSA-232r-66cg-79px ↗
CVE CVE-2018-7750 ↗

CWEs

CWE id Name
CWE-287 Improper Authentication

Affected packages (7)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip paramiko >= 2.0.0, < 2.0.8 2.0.8 —
pip paramiko >= 2.1.0, < 2.1.5 2.1.5 —
pip paramiko >= 2.2.0, < 2.2.3 2.2.3 —
pip paramiko >= 2.3.0, < 2.3.2 2.3.2 —
pip paramiko = 2.4.0 2.4.1 —
pip paramiko >= 1.18.0, < 1.18.5 1.18.5 —
pip paramiko < 1.17.6 1.17.6 —

References

cvelogic Threat Intelligence