Executive brief
Spring Cloud Config Server is used by enterprises to manage application configuration across multiple services. A time-of-check-time-of-use (TOCTOU) race condition in the SVN repository cloning mechanism allows an attacker to manipulate the base directory during the checkout process, potentially leading to arbitrary code execution or configuration tampering on affected servers.
Technical details
The vulnerability is a time-of-check-time-of-use (TOCTOU) race condition in the spring.cloud.config.server.svn.basedir parameter used when cloning SVN repositories. An attacker with network access to the Spring Cloud Config Server can exploit the window between directory validation and actual file operations to perform directory substitution or symlink attacks. This allows arbitrary file write or read access with the privileges of the Config Server process. The vulnerability affects Spring Cloud Config versions 3.1.14 and earlier, 4.0.0 through 4.2.8, 4.3.0 through 4.3.4, and 5.0.0 through 5.0.4. Patches are available for affected versions.
Affected products
- VMware Spring Cloud Config 3.1.14 and earlier, 4.0.0–4.2.8, 4.3.0–4.3.4, 5.0.0–5.0.4
Timeline
- 2026-08-26: disclosed