CVE-2020-15069
Sophos XG Firewall Buffer Overflow Vulnerability
Executive Summary
CVE-2020-15069 is a critical severity vulnerability affecting binary-analysis. It is classified as an undisclosed flaw. This vulnerability is actively being exploited in the wild.
Precogs AI Insight
"This critical flaw stems from within Sophos XG Firewall, allowing an architectural oversight in input validation. Adversaries commonly weaponize this defect by execute arbitrary code on the target system, potentially leading to full system compromise. Precogs identifies insecure dynamic linking patterns without requiring source code access to prevent unauthorized logical exploitation."
What is this vulnerability?
CVE-2020-15069 is categorized as a critical Buffer Overflow flaw. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
Sophos XG Firewall contains a buffer overflow vulnerability that allows for remote code execution via the "HTTP/S bookmark" feature..
This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.
Risk Assessment
| Metric | Value |
|---|---|
| CVSS Base Score | 9.8 (CRITICAL) |
| Vector String | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| Published | February 6, 2025 |
| Last Modified | February 6, 2025 |
| Related CWEs | N/A |
Impact on Systems
✅ Remote Code Execution: Attackers can overwrite the instruction pointer (EIP/RIP) to redirect execution to malicious shellcode.
✅ Memory Corruption: Overwriting adjacent memory regions can corrupt critical application state, leading to unpredictable privilege escalation.
✅ Denial of Service: Triggering segmentation faults and kernel panics results in immediate disruption of critical systems.
How to fix this issue?
Implement the following strategic mitigations immediately to eliminate the attack surface.
1. Memory-Safe Languages Where possible, migrate critical parsing logic to memory-safe languages like Rust or Go.
2. Safe Standard Libraries Replace unbounded C functions (strcpy, sprintf) with boundary-checking equivalents (strncpy, snprintf).
3. Compiler Defenses Ensure software is compiled with modern defensive flags: ASLR, DEP/NX, Stack Canaries (SSP), and Position Independent Executables (PIE).
Vulnerability Signature
// Vulnerable C Function
void parse_network_packet(char *untrusted_data) \{
char local_buffer[128];
// VULNERABLE: strcpy does not verify the length of the source data
strcpy(local_buffer, untrusted_data);
printf("Packet Processed.");
\}
// EXPLOIT PAYLOAD: 128 bytes of padding + [Overwrite EIP Address]
References and Sources
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | Network packet or file input |
| Vector | Data exceeds the allocated buffer bounds during a copy operation |
| Sink | strcpy(), memcpy(), or pointer arithmetic |
| Impact | Memory corruption, Remote Code Execution (RCE) |
Vulnerable Code Pattern
// ❌ VULNERABLE: Memory Corruption
void process_data(char *input) {
char buffer[128];
// Taint sink: copies without bounds checking
strcpy(buffer, input);
}
Secure Code Pattern
// ✅ SECURE: Bounded Memory Operations
void process_data(char *input) {
char buffer[128];
// Sanitized boundary check
strncpy(buffer, input, sizeof(buffer) - 1);
buffer[sizeof(buffer) - 1] = '\0';
}
How Precogs Detects This
Precogs Binary SAST engine explicitly uncovers memory boundary violations and unsafe memory management functions in compiled binaries.\n