CVE-2025-60686: totolink a720r_firmware Stack-based Buffer Overflow

Vulnerability summary

CVE-2025-60686 is a medium (CVSS 5.1) Stack-based Buffer Overflow vulnerability in totolink a720r_firmware. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 13.8% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 13-11-2025
   PublishedVulnerability first disclosed.
2. 05-07-2026
   Last modifiedVulnerability information updated.

Description

A local stack-based buffer overflow vulnerability exists in the infostat.cgi and cstecgi.cgi binaries of ToToLink routers (A720R V4.1.5cu.614_B20230630, LR1200GB V9.1.0u.6619_B20230130, and NR1800X V9.1.0u.6681_B20230703). Both programs parse the contents of /proc/net/arp using sscanf() with "%s" format specifiers into fixed-size stack buffers without length validation. Specifically, one function writes user-controlled data into a single-byte buffer, and the other into adjacent small arrays without bounds checking. An attacker who controls the contents of /proc/net/arp can trigger memory corruption, leading to denial of service or potential arbitrary code execution.

• 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).