CVE-2025-7853: Critical Stack-Based Buffer Overflow Vulnerability in Tenda FH451 Router
🔍 TL;DR Summary
A critical vulnerability (CVE-2025-7853) has been discovered in Tenda FH451 version 1.0.0.9. This stack-based buffer overflow in the fromSetIpBind function allows a remote attacker with low privileges to execute arbitrary code on the device. A proof-of-concept exploit is publicly available, increasing the urgency for users to apply necessary security measures.
🚨 Vulnerability Details
- CVE ID: CVE-2025-7853
- Description: A stack-based buffer overflow vulnerability exists in the
fromSetIpBindfunction of the Tenda FH451 router, version 1.0.0.9. By manipulating thepageargument, an attacker can overwrite the stack and potentially execute arbitrary code. - CVSS Score: 8.8 (HIGH)
- CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CVSS Explanation: This CVSS vector indicates the vulnerability is remotely exploitable over the network (AV:N) with low attack complexity (AC:L). An attacker with low privileges (PR:L) can trigger the vulnerability without any user interaction (UI:N), leading to high impact on confidentiality (C:H), integrity (I:H), and availability (A:H).
- Exploit Requirements: An attacker needs to be authenticated with low privileges to exploit the vulnerability. The vulnerable function is accessible via HTTP requests.
- Affected Vendor: Tenda
- Affected Product: FH451
- Affected Version: 1.0.0.9
- CWE: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), CWE-121 (Stack-based Buffer Overflow)
- CWE Explanation: CWE-119 and CWE-121 describe the classic buffer overflow scenario. When a program writes data beyond the allocated buffer size on the stack, it can overwrite adjacent memory regions, leading to crashes or, more seriously, arbitrary code execution.
📅 Timeline of Events
- 2025-07-19: Vulnerability reported and CVE ID assigned (CVE-2025-7853).
- 2025-07-19: Public disclosure of the vulnerability and proof-of-concept exploit.
🧠 Exploitability & Real-World Risk
The existence of a public proof-of-concept (PoC) significantly increases the risk associated with CVE-2025-7853. Attackers can readily leverage the PoC to develop exploits and compromise vulnerable Tenda FH451 routers. Given the widespread use of routers in home and small business networks, this vulnerability presents a substantial threat, potentially enabling attackers to gain unauthorized access to internal networks, steal sensitive data, or use the compromised devices for malicious activities such as botnet participation.
🛠️ Recommendations
Users of Tenda FH451 version 1.0.0.9 are strongly advised to take the following actions:
- Check for Firmware Updates: Visit the Tenda website and check for available firmware updates for the FH451 router. Apply the latest firmware as soon as it is released.
- Disable Remote Management: If remote management is enabled, disable it to reduce the attack surface.
- Restrict Access: Limit access to the router's configuration interface to trusted devices only.
- Monitor Network Traffic: Monitor network traffic for any suspicious activity.
🧪 Technical Insight
The vulnerability lies in the fromSetIpBind function, which handles HTTP requests related to IP address binding. By crafting a malicious HTTP request with an overly long page argument, an attacker can overflow the stack buffer, overwriting return addresses and potentially injecting malicious code. This code can then be executed when the function returns, giving the attacker control of the device.
🙌 Credit to Researcher(s)
This vulnerability was discovered and reported by panda666-888.
🔗 References
🧵 Tags
#CVE-2025-7853 #Tenda #FH451 #Router #StackBufferOverflow #RCE #Vulnerability #Exploit #Firmware
Summary: A critical stack-based buffer overflow vulnerability (CVE-2025-7853) affects Tenda FH451 version 1.0.0.9, allowing remote attackers with low privileges to execute arbitrary code. A public proof-of-concept exploit exists, making immediate patching essential.
CVE ID: CVE-2025-7853
Risk Analysis: Successful exploitation can lead to complete control of the router, allowing attackers to intercept traffic, modify settings, and potentially pivot to other devices on the network. This poses a significant risk to confidentiality, integrity, and availability.
Recommendation: Update the firmware to the latest version, disable remote management, restrict access to the configuration interface, and monitor network traffic for suspicious activity.
Timeline
- 2025-07-19: Vulnerability reported and CVE ID assigned (CVE-2025-7853). Public disclosure of vulnerability and PoC.