VulnerabilityPublished 22 Oct 2025Updated 23 Oct 2025

CVE-2025-60335: TOTOLINK N600R · NULL Pointer Dereference

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 2.1% chance of exploitation in 30 days – higher than 81% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Immediately audit network environments to identify any TOTOLINK N600R routers running the vulnerable firmware version 4.3.0cu.7866_B20220506.
Restrict access to router management interfaces by implementing network segmentation and firewall rules to allow only trusted IP addresses.
Disable remote HTTP management access if not required, or replace it with more secure management protocols such as HTTPS or VPN-based access.
Monitor network traffic for unusual HTTP requests targeting router management interfaces that could indicate exploitation attempts.
Engage with TOTOLINK support channels to obtain information about upcoming patches or firmware updates addressing this vulnerability and apply them promptly once available.
Consider replacing vulnerable devices with alternative routers that receive timely security updates if patching is not feasible.
Implement network redundancy and failover mechanisms to minimize impact in case of device failure due to exploitation.
Educate IT staff about this vulnerability and ensure incident response plans include procedures for handling router DoS events.

Description

A NULL pointer dereference in the main function of TOTOLINK N600R v4.3.0cu.7866_B20220506 allows attackers to cause a Denial of Service (DoS) via a crafted HTTP request.

Impact

For European organizations, exploitation of CVE-2025-60335 could lead to denial of service on network edge devices, causing loss of internet connectivity or internal network segmentation failures. This can disrupt business operations, remote work, and access to cloud services. Critical infrastructure sectors such as healthcare, finance, and government agencies using TOTOLINK N600R routers may experience outages affecting service availability and operational continuity. The vulnerability's remote exploitability without authentication increases risk, especially for devices exposed to the internet or poorly segmented internal networks. While no data confidentiality or integrity is directly impacted, the availability loss can have cascading effects on dependent systems and services. Organizations with limited IT support or patch management capabilities may face prolonged downtime. The absence of known exploits currently provides a window for proactive mitigation, but the threat remains significant given the ease of triggering the DoS condition.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/z472421519/BinaryAudit/blob/main/PoC/NPD/TOTOLink/main/CONTENT_LENGTH_MAX.md (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 29 Oct 2025, 18:08 UTC

WeaknessesCWE-476

Technical details

References

Community reviews

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