Cyber Resilience

CVE-2025-5600

CriticalPublic PoC

Published: 04 June 2025

Published
04 June 2025
Modified
10 June 2025
KEV Added
Patch
CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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
EPSS Score 0.0120 79.3th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-5600 is a critical-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Totolink Ex1200T Firmware. Its CVSS base score is 9.3 (Critical).

Operationally, ranked in the top 20.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

A critical stack-based buffer overflow vulnerability, tracked as CVE-2025-5600, affects the TOTOLINK EX1200T wireless router running firmware version 4.1.2cu.5232_B20210713. The flaw resides in the setLanguageCfg function within /cgi-bin/cstecgi.cgi, where improper handling of the LangType argument permits an out-of-bounds write on the stack, corresponding to CWE-119, CWE-121, and CWE-787. The issue carries a CVSS 4.0 score of 9.3 and can be triggered over the network without authentication or user interaction.

An unauthenticated remote attacker can send a crafted HTTP request to the CGI endpoint, causing memory corruption that may result in arbitrary code execution, denial of service, or full device compromise. Public exploit code has already been disclosed, enabling straightforward reproduction by attackers with network access to the router's management interface.

The associated EPSS score remains flat at a low 0.0120 with no material increase since disclosure, indicating limited observed exploitation interest to date. No vendor patch or mitigation guidance is referenced in the available advisories.

EU & UK References

Vulnerability details

A vulnerability, which was classified as critical, has been found in TOTOLINK EX1200T 4.1.2cu.5232_B20210713. This issue affects the function setLanguageCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument LangType leads to stack-based buffer overflow. The attack may be initiated…

more

remotely. The exploit has been disclosed to the public and may be used.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

totolink
ex1200t firmware
4.1.2cu.5232_b20210713

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-119 CWE-787

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-119

Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

References