CVE-2024-12805: SonicOS Format String RCE Vulnerability

CVE-2024-12805 Overview

CVE-2024-12805 is a post-authentication format string vulnerability in the SonicOS management interface. A remote attacker with high privileges can send crafted input containing format specifiers to trigger a crash of the firewall. The flaw may also lead to arbitrary code execution on the affected device. SonicWall documented the issue in advisory SNWLID-2025-0004. The weakness is classified as [CWE-134] Use of Externally-Controlled Format String. Because SonicOS runs on network edge appliances, successful exploitation directly affects perimeter availability and integrity.

Critical Impact
An authenticated remote attacker can crash the SonicOS firewall and potentially achieve code execution on the appliance, compromising perimeter defenses.

Affected Products

SonicWall SonicOS management interface
SonicWall firewall appliances running vulnerable SonicOS versions as listed in SNWLID-2025-0004
Refer to the SonicWall Security Advisory SNWLID-2025-0004 for the full affected version matrix

Discovery Timeline

2025-01-09 - CVE-2024-12805 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-12805

Vulnerability Analysis

The vulnerability resides in the SonicOS management plane, where user-supplied input is passed directly to a formatting function without sanitization. Format string flaws occur when attacker-controlled data reaches functions such as printf, sprintf, or syslog as the format argument. Format specifiers like %s, %x, and %n are then interpreted by the function, exposing memory contents or corrupting memory. In this case, the flaw is reachable only after successful authentication to the management interface, requiring valid administrative credentials.

Once triggered, the malformed format string can dereference invalid pointers and crash the firewall process, producing a denial-of-service condition. If the attacker crafts specifiers such as %n, they may write attacker-controlled values to memory and pivot toward code execution on the appliance. The EPSS score is 0.709%, placing it in the 49th percentile for exploitation likelihood.

Root Cause

The root cause is [CWE-134]: user-controlled input is used as the format string argument to a variadic formatting function inside the SonicOS management code. Proper implementations pass user input as a %s argument rather than as the format specifier itself. The absence of this control allows format specifiers to be parsed from attacker input.

Attack Vector

An attacker must first authenticate to the SonicOS management interface with high-privilege credentials. The attacker then submits a request to a vulnerable management endpoint containing format specifier tokens. SonicWall has not published exploit details, and no public proof-of-concept is available at the time of writing.

No verified exploit code is available. See the SonicWall Security Advisory SNWLID-2025-0004 for vendor-provided technical context.

Detection Methods for CVE-2024-12805

Indicators of Compromise

Unexpected restarts or crashes of the SonicOS management process or the appliance itself
Management-interface log entries containing format specifier tokens such as %s, %x, %n, or %p submitted as parameter values
Administrative sessions originating from unexpected source addresses or geographies preceding a crash event

Detection Strategies

Monitor SonicOS audit logs for authenticated management requests containing repeated % characters or format specifier sequences in input fields
Correlate administrative login events with subsequent appliance reboots or watchdog-triggered restarts
Alert on repeated failed or successful high-privilege logins from a single source followed by management-plane errors

Monitoring Recommendations

Forward SonicOS syslog data to a centralized SIEM for retention and correlation across appliances
Enable and review audit logging for all administrative accounts on the firewall
Track firmware version drift across the fleet to identify appliances still running vulnerable SonicOS builds

How to Mitigate CVE-2024-12805

Immediate Actions Required

Apply the fixed SonicOS firmware version identified in SonicWall Security Advisory SNWLID-2025-0004
Restrict management-interface access to a dedicated administrative network or trusted jump hosts
Rotate administrative credentials on any appliance that may have been exposed to untrusted networks
Enforce multi-factor authentication for all SonicOS administrative accounts

Patch Information

SonicWall has released fixed SonicOS firmware addressing CVE-2024-12805. Administrators should consult the vendor advisory SNWLID-2025-0004 for exact fixed versions per platform family and follow the vendor upgrade procedure. Verify firmware integrity after upgrade and confirm the running version on each appliance.

Workarounds

Limit HTTPS and SSH management access to specific trusted source IP addresses using the appliance access rules
Disable WAN-side management access where operationally feasible until patching is complete
Require VPN connectivity into a management network before allowing access to the SonicOS interface

bash

# Example: restrict management access to a trusted subnet (illustrative)
# Consult SonicWall documentation for exact CLI syntax for your firmware
config
  administration
    management-access allow-networks 10.10.0.0/24
    management-access deny-networks any
  commit