CVE-2023-43239
Published: 21 September 2023
Summary
CVE-2023-43239 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Dlink Dir-816 A2 Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 1.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis
D-Link DIR-816 A2 firmware version 1.10CNB05 contains a stack-based buffer overflow vulnerability (CWE-121, CWE-787) triggered by the flag_5G parameter in the showMACfilterMAC function. The flaw permits an out-of-bounds write on the stack when the device processes a crafted HTTP request to its web management interface.
Unauthenticated attackers with network access can send a malicious request that overflows the stack, leading to remote code execution, denial of service, or full device compromise. The vulnerability carries a CVSS 3.1 score of 9.8, reflecting that no authentication or user interaction is required and the attack can be performed remotely with low complexity.
Public references include a detailed proof-of-concept on GitHub and D-Link’s security bulletin page, which lists affected hardware and directs users to firmware updates or configuration guidance. The EPSS score has reached a peak of 0.6064 with a current value of 0.5799, indicating sustained exploitation interest after disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-47658
Vulnerability details
D-Link DIR-816 A2 v1.10CNB05 was discovered to contain a stack overflow via parameter flag_5G in showMACfilterMAC.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
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.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.