CVE-2024-55660: 
Homebrew vulnerability analysis and mitigation

SiYuan is a personal knowledge management system that was found to contain a Server-Side Template Injection (SSTI) vulnerability. Prior to version 3.1.16, SiYuan's /api/template/renderSprig endpoint was vulnerable to SSTI through the Sprig template engine. Although the engine has limitations, it allowed attackers to access environment variables. The vulnerability was discovered and disclosed on December 11, 2024 (GitHub Advisory).

The vulnerability exists in the /api/template/renderSprig endpoint which uses the Sprig template engine. The issue allows for Server-Side Template Injection that could expose environment variables through template functions like 'env' and 'expandenv'. The vulnerability has been assigned a CVSS v4.0 Base Score of 6.9 (Medium) with the vector string CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N (NVD).

The primary impact of this vulnerability is information leakage through access to environment variables. While the Sprig template engine has certain limitations, successful exploitation could allow attackers to access sensitive configuration data stored in environment variables (GitHub Advisory).

The vulnerability has been patched in version 3.1.16. The fix involves removing potentially dangerous functions from the template engine, specifically the 'env', 'expandenv', and 'getHostByName' functions (GitHub Commit). Users are advised to upgrade to version 3.1.16 or later to address this security issue.