CVE-2024-43798 | Chisel AUTH environment variable not respected in server entrypoint

Chisel is a fast TCP/UDP tunnel, transported over HTTP, secured via SSH. The Chisel server doesn't ever read the documented `AUTH` environment variable used to set credentials, which allows any unauthenticated user to connect, even if credentials were set. Anyone running the Chisel server that is using the `AUTH` environment variable to specify credentials to authenticate against is affected by this vulnerability. Chisel is often used to provide an entrypoint to a private network, which means services that are gated by Chisel may be affected. Additionally, Chisel is often used for exposing services to the internet. An attacker could MITM requests by connecting to a Chisel server and requesting to forward traffic from a remote port. This issue has been addressed in release version 1.10.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Published: 2024-08-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2024-43798 is rated Moderate Risk (47.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.45%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-43798

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.45% +0.42%
2 2025-11-21 0.40% 0.03% -0.37%
3 2025-11-18 0.40%

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-43798

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N 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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 4.0 [email protected]

Weakness enumeration for CVE-2024-43798

GitHub Security Advisory for CVE-2024-43798

GHSA-38jh-8h67-m7mj · Severity: high · Ecosystem: go — Chisel's AUTH environment variable not respected in server entrypoint

Affected software / configurations for CVE-2024-43798

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2024-43798

cvelogic Threat Intelligence