Simple Web Server 2.2 rc2 contains a stack-based buffer overflow vulnerability in its handling of the Connection HTTP header. When a remote attacker sends an overly long string in this header, the server uses vsprintf() without proper bounds checking, leading to a buffer overflow on the stack. This flaw allows remote attackers to execute arbitrary code with the privileges of the web server process. The vulnerability is triggered before authentication.
https://www.vulncheck.com/advisories/simple-web-server-connection-header-buffer-overflow
https://www.exploit-db.com/exploits/20028
https://www.exploit-db.com/exploits/19937
Published: 2025-08-08
Updated: 2025-08-08
Base Score: 9.7
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: Critical
EPSS: 0.00499