CVE-2023-23931
Cipher.update_into can corrupt memory if passed an immutable python object as the outbuf
Executive Summary
CVE-2023-23931 is a critical severity vulnerability affecting binary-analysis. It is classified as an undisclosed flaw. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"Precogs Binary SAST/DAST engine performs deep structural analysis of compiled binaries, detecting memory corruption, control-flow hijacking, and privilege escalation vulnerabilities without requiring source code access."
What is this vulnerability?
CVE-2023-23931 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.
Previously, Cipher.update_into would accept Python objects which implement the buffer protocol, but provide only immutable buffers:
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** | `N/A` |
| **Published** | February 7, 2023 |
| **Last Modified** | February 22, 2026 |
| **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
```javascript
// 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]