CVE-2024-32299 Overview
CVE-2024-32299 is a stack-based buffer overflow [CWE-121] in Tenda FH1203 routers running firmware version 2.0.1.6. The flaw resides in the fromWizardHandle function, which fails to validate the length of the PPW parameter before copying it onto the stack. An authenticated attacker on the network can send a crafted HTTP request to corrupt the return address and hijack execution flow. Successful exploitation can lead to arbitrary code execution on the device or a denial-of-service condition affecting the router.
Critical Impact
Network-adjacent attackers with low privileges can trigger memory corruption in the router's web management interface, enabling code execution and full compromise of the device.
Affected Products
- Tenda FH1203 router (hardware)
- Tenda FH1203 firmware version 2.0.1.6
- Deployments exposing the web management interface to untrusted networks
Discovery Timeline
- 2024-04-17 - CVE-2024-32299 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-32299
Vulnerability Analysis
The Tenda FH1203 web management daemon exposes a setup wizard handler named fromWizardHandle. This handler parses parameters from HTTP requests submitted to the administrative interface. The PPW parameter, which represents a PPPoE password value during initial configuration, is copied into a fixed-size stack buffer without proper length validation. Sending an oversized PPW string overflows the buffer and overwrites adjacent stack data, including the saved return address.
Because consumer router firmware typically lacks modern exploit mitigations such as stack canaries, address space layout randomization, and non-executable stacks, an attacker can reliably redirect execution to attacker-controlled data. The result is arbitrary code execution in the context of the web server, which usually runs with root privileges on embedded Linux router firmware.
Root Cause
The root cause is missing bounds checking on user-supplied input inside fromWizardHandle. The function uses an unsafe string copy pattern against a caller-controlled parameter, allowing the source length to exceed the destination buffer capacity on the stack.
Attack Vector
Exploitation requires network access to the router's HTTP management interface and low-privileged authentication. An attacker sends a POST request to the wizard endpoint with an oversized PPW value. When the handler processes the parameter, the stack frame is corrupted, allowing the attacker to gain control of the instruction pointer.
No public exploit code is included in this advisory. See the GitHub PoC Repository for technical details published by the reporter.
Detection Methods for CVE-2024-32299
Indicators of Compromise
- HTTP POST requests to router administrative endpoints containing abnormally long PPW parameter values, particularly requests targeting the setup wizard handler.
- Unexpected reboots, crashes, or watchdog resets of the FH1203 device following administrative traffic.
- New or unfamiliar processes, listening ports, or outbound connections from the router to external hosts.
Detection Strategies
- Inspect web server and syslog output from the router for malformed wizard requests and repeated crash signatures.
- Deploy network monitoring rules that flag HTTP parameters exceeding reasonable length thresholds directed at router management interfaces.
- Baseline administrative traffic and alert on requests from non-administrative subnets to router configuration endpoints.
Monitoring Recommendations
- Log all authentication attempts against the router web interface and correlate failures with unusual request bodies.
- Monitor DNS and outbound traffic from the router itself for signs of post-exploitation callbacks.
- Track firmware version reporting across managed router fleets to identify unpatched Tenda FH1203 devices.
How to Mitigate CVE-2024-32299
Immediate Actions Required
- Restrict access to the router's web management interface so it is reachable only from trusted management VLANs or hosts.
- Disable remote WAN-side administration and change default administrative credentials to strong, unique values.
- Isolate affected Tenda FH1203 devices from sensitive network segments until a vendor fix is validated.
Patch Information
No vendor advisory or patched firmware release has been referenced in the NVD entry for CVE-2024-32299 at the time of publication. Organizations should monitor Tenda's support channels for firmware updates addressing the fromWizardHandle stack overflow and apply them promptly once available. If the vendor does not provide a fix, consider replacing the affected hardware with a supported platform.
Workarounds
- Block inbound access to TCP ports serving the router HTTP administration interface at the perimeter firewall.
- Enforce network segmentation so that only administrative workstations can reach the router management plane.
- Rotate PPPoE and administrative credentials and audit router configuration for unauthorized changes.
# Example ACL restricting router admin access to a management host
iptables -I INPUT -p tcp --dport 80 -s 192.0.2.10 -j ACCEPT
iptables -I INPUT -p tcp --dport 80 -j DROP
iptables -I INPUT -p tcp --dport 443 -s 192.0.2.10 -j ACCEPT
iptables -I INPUT -p tcp --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
