Overview
The vulnerability in focus, CVE-2025-54895, is a critical security flaw affecting the Windows Security Provider Negotiator (SPNEGO) Extended Negotiation. The vulnerability arises due to an integer overflow or wraparound, which could be exploited by an authorized attacker to elevate privileges locally. This vulnerability, while requiring local access, could potentially lead to system compromise or data leakage, highlighting the importance of rapid mitigation.
Vulnerability Summary
CVE ID: CVE-2025-54895
Severity: High (7.8)
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Impact: System compromise or data leakage due to local privilege escalation
Affected Products
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Product | Affected Versions
Windows SPNEGO | All previous versions prior to patch
How the Exploit Works
The exploit leverages an integer overflow or wraparound in the Windows SPNEGO Extended Negotiation. This flaw allows an authorized local attacker to manipulate the overflow to corrupt memory, elevate their privileges, and execute arbitrary code. This could lead to unauthorized system access, potential system compromise, or data leakage.
Conceptual Example Code
Below is a conceptual example of how the vulnerability might be exploited. This pseudocode demonstrates the manipulation of the integer overflow to elevate privileges.
#include <windows.h>
int main() {
// Initialize SPNEGO negotiation
SPNEGOHandle handle = SPNEGO_Init();
// Create integer overflow
int overflow = INT_MAX + 1;
// Use overflow to corrupt memory and elevate privileges
SPNEGO_Negotiate(handle, overflow);
// Execute arbitrary code with elevated privileges
system("malicious_command");
return 0;
}Mitigation Guidance
Users are advised to apply the latest vendor patches as soon as possible to remediate this vulnerability. If patches cannot be applied immediately, the use of a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) may offer temporary mitigation. However, these are not long-term solutions as they do not address the underlying vulnerability.
