CVE-2024-43798

Chisel AUTH environment variable not respected in server entrypoint

HIGH
8.6
CVSS Score
Published: August 26, 2024 at 10:32 PM UTC
Updated: June 17, 2026 at 07:51 AM UTC
1 product affected across 1 vendorChisel

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Severity
HIGH8.6
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.10.0
Affected range stops below 1.10.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.6HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-306CWE-1068

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