CVE-2025-67445
DoS in Totolink X5000R Firmware 9.1.0cu.2415_b20250515
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-67445 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Totolink X5000R Firmware. Its CVSS base score is 7.5 (High).
Operationally, ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-67445 is a denial-of-service vulnerability in the TOTOLINK X5000R router firmware version V9.1.0cu.2415_B20250515. The flaw exists in the /cgi-bin/cstecgi.cgi script, which reads the CONTENT_LENGTH environment variable and allocates memory using malloc(CONTENT_LENGTH + 1) without sufficient bounds checking. When the lighttpd web server's request size limit is not enforced, this mishandling enables memory exhaustion or a segmentation fault in the management CGI.
The vulnerability can be exploited by any unauthenticated attacker with network access to the device. By crafting and sending a large POST request, the attacker triggers uncontrolled memory allocation, crashing the CGI process and rendering the web management interface unavailable. It carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and maps to CWE-400 (Uncontrolled Resource Consumption).
Vendor guidance and further details, including potential patches or workarounds, are available at http://totolink.com. Additional technical analysis and a proof-of-concept are provided in the GitHub repository https://github.com/DaRkSpOoOk/CVE-2025-67445.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-208091
Vulnerability Data
TOTOLINK X5000R V9.1.0cu.2415_B20250515 contains a denial-of-service vulnerability in /cgi-bin/cstecgi.cgi. The CGI reads the CONTENT_LENGTH environment variable and allocates memory using malloc (CONTENT_LENGTH + 1) without sufficient bounds checking. When lighttpd s request size limit is not enforced, a crafted large…
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POST request can cause memory exhaustion or a segmentation fault, leading to a crash of the management CGI and loss of availability of the web interface.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.
SC-6 enforces explicit allocation limits on resources, structurally preventing the weakness from occurring.
Process isolation confines resource consumption to separate domains, reducing blast radius without stopping the root flaw.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.
A.8.6's monitoring, stress-testing, projections, tuning, demand-reduction steps (e.g. optimizing queries, deleting obsolete data, restricting non-critical bandwidth) and capacity planning directly stop most uncontrolled consumption from being exploitable by keeping resources within safe bounds; the bounded remainder is algorithmic flaws (e.g. infinite loops, uncontrolled recursion) that no amount of capacity planning can prevent from exhausting a resource when triggered.
Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.
Monitoring network service usage and applying controls to restrict access when necessary limits an attacker’s ability to consume excessive resources through unrestricted or unauthenticated service calls.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-400, a class-level weakness. Rules are authored against its narrower children: CWE-770.