CVE-2021-34861: d-link dap-2020 Stack-based Buffer Overflow

Vulnerability summary

CVE-2021-34861 is a high (CVSS 8.8) Stack-based Buffer Overflow vulnerability in d-link dap-2020. EPSS estimates a 0.82% chance of exploitation in the next 30 days, higher than 56.5% of scored vulnerabilities.

Timeline

1. 25-10-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DAP-2020 1.01rc001 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the webproc endpoint, which listens on TCP port 80 by default. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12104.

• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).