CVE-2024-12803: SonicOS Buffer Overflow Vulnerability

CVE-2024-12803 Overview

CVE-2024-12803 is a post-authentication stack-based buffer overflow [CWE-121] in the SonicWall SonicOS management interface. An authenticated remote attacker with high privileges can send crafted input that overflows a fixed-size stack buffer. The condition crashes the firewall and may allow arbitrary code execution in the management process context.

The vulnerability affects network perimeter devices, so successful exploitation can disrupt inline traffic filtering and expose downstream networks. SonicWall published advisory SNWLID-2025-0004 describing the flaw and remediation. The CVE was published to the National Vulnerability Database on January 9, 2025.

Critical Impact
An authenticated attacker can crash the firewall or execute code on the management plane, disrupting perimeter defenses and network availability.

Affected Products

SonicWall SonicOS management interface
SonicWall firewall appliances running affected SonicOS builds
Refer to SonicWall Security Advisory SNWLID-2025-0004 for the full list of affected versions

Discovery Timeline

2025-01-09 - CVE-2024-12803 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-12803

Vulnerability Analysis

The flaw resides in the SonicOS management plane, which processes administrative requests over the network. A specific management input path writes attacker-controlled data into a fixed-size stack buffer without validating the length against the destination boundary. When the input exceeds the buffer size, adjacent stack memory including saved return addresses is overwritten.

The most direct consequence is a process crash that renders the firewall unresponsive. On devices lacking stack protection mitigations or when the corruption occurs before canary checks, the corrupted return address can redirect execution flow. This may enable arbitrary code execution in the privileged management process.

The attack requires authentication with administrative privileges, which limits opportunistic exploitation. However, credential theft, phishing, or misuse by insiders remains a realistic path. Compromise of a perimeter firewall exposes internal segmentation, VPN tunnels, and inspection policies.

Root Cause

The root cause is missing or incorrect bounds checking in a management input handler [CWE-121]. The function copies user-supplied data into a stack-allocated buffer using an unsafe copy operation. Because the size check does not enforce the destination buffer limit, oversized input corrupts the stack frame.

Attack Vector

The attack is network-reachable through the SonicOS management interface. An authenticated administrator sends a crafted request containing an oversized parameter to the vulnerable handler. See the SonicWall advisory for the specific vulnerable component and technical details.

Detection Methods for CVE-2024-12803

Indicators of Compromise

Unexpected reboots, watchdog resets, or crash dumps on the firewall management process
Management interface sessions from unusual source addresses or outside change windows
Administrator logins followed by malformed or oversized management requests
Gaps in firewall logging or telemetry consistent with a management-plane crash

Detection Strategies

Alert on repeated SonicOS management process crashes correlated with prior admin authentication events
Monitor management HTTP/HTTPS traffic for abnormally large request bodies or parameters targeting admin endpoints
Track administrator account activity against a baseline of expected source networks and time windows
Correlate firewall syslog events with authentication logs to surface post-login anomalies

Monitoring Recommendations

Forward SonicOS syslog and audit events to a centralized log platform for retention and correlation
Enable alerting on management-plane restarts, HA failover events, and admin credential changes
Restrict management access to a dedicated administrative network and log all attempts from other sources
Review external references such as SNWLID-2025-0004 for vendor-specific detection guidance

How to Mitigate CVE-2024-12803

Immediate Actions Required

Apply the SonicOS firmware update referenced in SNWLID-2025-0004 as soon as maintenance windows allow
Restrict management interface access to trusted administrative subnets and jump hosts only
Enforce multi-factor authentication for all SonicOS administrator accounts
Rotate administrator credentials if unauthorized management access is suspected

Patch Information

SonicWall has published fixed firmware versions in advisory SNWLID-2025-0004. Consult the SonicWall PSIRT advisory for the specific fixed builds mapped to each affected platform and follow the vendor upgrade procedure.

Workarounds

Disable remote management on WAN interfaces and require VPN access to reach the management plane
Apply access rules that limit HTTPS management traffic to a small list of administrator source IPs
Reduce the number of privileged accounts and audit existing administrator role assignments
Where patching must be delayed, increase monitoring frequency for management-plane crashes and admin logins

bash

# Example: restrict SonicOS management access to a trusted admin subnet
# Replace X.X.X.X/YY with your administrative network
# 1. Disable HTTPS management on WAN
# 2. Create an address object for the admin subnet
# 3. Add an access rule permitting only that object to the management service
# Follow the SonicWall administration guide for platform-specific CLI/GUI steps