CVE-2025-12239: totolink a3300r_firmware

Vulnerability summary

CVE-2025-12239 is a critical (CVSS 9.8) vulnerability in totolink a3300r_firmware. EPSS estimates a 0.84% chance of exploitation in the next 30 days, higher than 57.2% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 27-10-2025
   PublishedVulnerability first disclosed.
2. 27-10-2025
   Last modifiedVulnerability information updated.

Description

A weakness has been identified in TOTOLINK A3300R 17.0.0cu.557_B20221024. The impacted element is the function setDdnsCfg of the file /cgi-bin/cstecgi.cgi. Executing manipulation can lead to buffer overflow. The attack may be performed from remote. The exploit has been made available to the public and could be exploited.

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.