CVE-2025-6121
Published: 16 June 2025
Summary
CVE-2025-6121 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Dlink Dir-632 Firmware. Its CVSS base score is 8.9 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 20.0% 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-2025-6121 and assigned CWE-119 and CWE-121, exists in the get_pure_content function of the HTTP POST Request Handler on the D-Link DIR-632 running firmware FW103B08. The flaw is triggered by manipulation of the Content-Length argument supplied in an HTTP POST request and carries a CVSS 4.0 score of 8.9.
An unauthenticated remote attacker can send a crafted POST request to trigger the overflow, resulting in arbitrary code execution or a denial-of-service condition on the device. Public proof-of-concept code has been released, confirming that exploitation is possible over the network without any user interaction or credentials.
The affected router model is no longer supported by D-Link, and the supplied references contain only disclosure and exploit details rather than vendor patches or mitigation guidance. The associated EPSS score has remained flat at 0.0129 with no material increase since publication.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-18394
Vulnerability details
A vulnerability, which was classified as critical, has been found in D-Link DIR-632 FW103B08. Affected by this issue is the function get_pure_content of the component HTTP POST Request Handler. The manipulation of the argument Content-Length leads to stack-based buffer overflow.…
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The attack may be launched remotely. The exploit has been disclosed to the public and may be used. This vulnerability only affects products that are no longer supported by the maintainer.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack-based buffer overflow in HTTP POST request handler (get_pure_content via Content-Length) in D-Link DIR-632 router's unauthenticated web interface enables remote exploitation of a public-facing application.
Affected Assets
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.
Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.
Managed runtimes used by platform-independent applications (e.g., JVM, CLR) enforce memory safety, preventing most buffer overflows that require direct memory manipulation.
Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.
Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.