Vulnerability · Published Oct 4, 2023 · Assigned by GitHub_M
CVE-2023-43809Soft Serve Public Key Authentication Bypass Vulnerability when Keyboard-Interactive SSH Authentication is Enabled
High 7.5
In plain English
A high-severity improper authentication in soft-serve from charmbracelet. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 69% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Soft Serve is a self-hostable Git server for the command line. Prior to version 0.6.2, a security vulnerability in Soft Serve could allow an unauthenticated, remote attacker to bypass public key authentication when keyboard-interactive SSH authentication is active, through the `allow-keyless` setting, and the public key requires additional client-side verification for example using FIDO2 or GPG. This is due to insufficient validation procedures of the public key step during SSH request handshake, granting unauthorized access if the keyboard-interaction mode is utilized. An attacker could exploit this vulnerability by presenting manipulated SSH requests using keyboard-interactive authentication mode. This could potentially result in unauthorized access to the Soft Serve. Users should upgrade to the latest Soft Serve version `v0.6.2` to receive the patch for this issue. To workaround this vulnerability without upgrading, users can temporarily disable Keyboard-Interactive SSH Authentication using the `allow-keyless` setting.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/charmbracelet/soft-serve | 0.6.2 | GHSA-mc97-99j4-vm2v |
| Go | github.com/charmbracelet/soft-serve | 0.6.2 | GO-2023-2097 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| charmbracelet | soft-serve | < 0.6.2 |
Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/charmbracelet/soft-serve/security/advisories/GHSA-mc97-99j4-vm2v x_refsource_CONFIRM
- https://github.com/charmbracelet/soft-serve/issues/389 x_refsource_MISC
- https://github.com/charmbracelet/soft-serve/commit/407c4ec72d1006cee1ff8c1775e5bcc091c2bc89 x_refsource_MISC
- https://github.com/charmbracelet/soft-serve/releases/tag/v0.6.2 x_refsource_MISC