CVE-2024-7721: 'MemFray' - The Stack Overflow That Broke the 'Secure' Gateway
Jan 2, 2026·4 min read·4 visits
Executive Summary (TL;DR)
The 'Fortress' Gateway loves speed so much it forgot how to count. By sending a specially crafted HTTP request with an oversized 'X-Custom-Auth' header, an attacker can overflow a stack buffer, overwrite the return address, and gain a root shell. No authentication required. CVSS 9.8. Patch immediately.
A critical stack-based buffer overflow in the core HTTP packet parser of the widely used 'Fortress' Secure Gateway appliance allows unauthenticated remote attackers to execute arbitrary code with root privileges. The vulnerability stems from an insecure implementation of a custom string copying routine designed for 'performance optimization'.
Fix Analysis (1)
Technical Appendix
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected Systems
Affected Versions Detail
| Product | Affected Versions | Fixed Version |
|---|---|---|
Fortress OS Fortress Networks | >= 4.0.0, < 4.2.1 | 4.2.1 |
| Attribute | Detail |
|---|---|
| CWE ID | CWE-121 (Stack-based Buffer Overflow) |
| CVSS v3.1 | 9.8 (Critical) |
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Attack Vector | Network (HTTP) |
| Exploit Status | Functional PoC Available |
| EPSS Score | 0.9245 (High Probability) |
MITRE ATT&CK Mapping
A stack-based buffer overflow condition exists when a program writes to a memory address on the program's call stack outside of the intended data structure.