CVE-2025-5839: Tenda AC9 POST Request AdvSetLanip fromadvsetlanip buffer overflow

Vulnerability summary

CVE-2025-5839 is a high (CVSS 9.0) vulnerability in tenda ac9_firmware. EPSS estimates a 1.02% chance of exploitation in the next 30 days, higher than 62.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 07-06-2025
   PublishedVulnerability first disclosed.
2. 09-06-2025
   Last modifiedVulnerability information updated.

Description

A vulnerability, which was classified as critical, has been found in Tenda AC9 15.03.02.13. Affected by this issue is the function fromadvsetlanip of the file /goform/AdvSetLanip of the component POST Request Handler. The manipulation of the argument lanMask leads to buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.

• 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.