CVE-2025-6486: Critical Stack Buffer Overflow in TOTOLINK A3002R Router
TOTOLINK A3002R routers are vulnerable to a critical stack-based buffer overflow, potentially allowing attackers to gain complete control of affected devices. This vulnerability, identified as CVE-2025-6486, impacts devices running firmware version 1.1.1-B20200824.0128.
Vulnerability Details
- CVE ID: CVE-2025-6486
- Description: A stack-based buffer overflow vulnerability exists in the
formWlanMultipleAPfunction of the/boafrm/formWlanMultipleAPfile within TOTOLINK A3002R firmware version 1.1.1-B20200824.0128. This can be triggered by manipulating thesubmit-urlargument. - CVSS Score and Vector:
- CVSS 3.1: 8.8 (High) -
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0: 7.4 (High) -
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Explanation: This means an attacker on the network with low-level privileges (e.g., a valid user account) can remotely execute arbitrary code on the router without any user interaction, potentially compromising confidentiality, integrity, and availability. The exploit is currently a Proof of Concept, meaning it's been demonstrated but may not be fully weaponized.
- CVSS 3.1: 8.8 (High) -
- Exploit Requirements: Attacker needs network access and valid credentials to log into the router's administrative interface.
- Affected Vendor, Product, Version: TOTOLINK A3002R, version 1.1.1-B20200824.0128
- CWE: CWE-121 - Stack-based Buffer Overflow.
Explanation: A stack buffer overflow occurs when a program writes beyond the allocated memory region on the stack, potentially overwriting critical data and leading to arbitrary code execution.
Timeline of Events
- 2025-06-22: Vulnerability publicly disclosed.
Exploitability & Real-World Risk
The existence of a public proof-of-concept exploit significantly increases the risk of this vulnerability being exploited in the wild. Attackers could leverage this flaw to:
- Gain complete control of the router.
- Modify DNS settings to redirect traffic to malicious websites.
- Install malware on connected devices.
- Use the compromised router as part of a botnet.
Recommendations
Unfortunately, at the time of writing, there is no official patch available. In the meantime, users are advised to:
- Change the default administrator password to a strong, unique password.
- Disable remote administration if not required.
- Monitor network traffic for any suspicious activity.
- Consider using a more secure router from a vendor with a better security track record if a patch isn't released quickly.
Technical Insight
The vulnerability lies in the insufficient bounds checking when handling the submit-url argument in the formWlanMultipleAP function. By providing an overly long string as the submit-url, an attacker can overwrite data on the stack, including the return address. When the function returns, it jumps to the attacker-controlled address, allowing them to execute arbitrary code.
Credit to Researcher(s)
This vulnerability was discovered and reported by wudipjq.
References
Tags
#CVE-2025-6486 #TOTOLINK #RouterSecurity #StackOverflow #RCE #Vulnerability
Summary: A critical stack-based buffer overflow vulnerability (CVE-2025-6486) has been discovered in TOTOLINK A3002R routers, allowing remote attackers with low-level privileges to potentially execute arbitrary code. Users are advised to take immediate steps to mitigate the risk.
CVE ID: CVE-2025-6486
Risk Analysis: Successful exploitation could allow an attacker to gain full control of the router, potentially leading to data breaches, service disruption, and the ability to launch further attacks on the network.
Recommendation: Change the default administrator password, disable remote administration if not required, monitor network traffic, and consider using a more secure router if a patch isn't released quickly.
Timeline
- 2025-06-22: Vulnerability publicly disclosed.