CVE-2025-13446CWE-119CWE-121

CVE-2025-13446

High · published November 20, 2025

CVSS v3.1
8.8
EPSS
4%
Percentile
90.9
In the wild
Unconfirmed
What it is

⚡ A remote attack can trigger a stack-based buffer overflow in Tenda AC21 routers! The vulnerable file, /goform/SetSysTimeCfg, makes it surprisingly easy for an attacker to exploit the timezone settings. 🔥 Think of this as a restaurant with a faulty reservation system — if a diner can tamper with the booking times, they might just push their dinner plans to the front of the queue, disrupting everything behind them. In this case, malicious input could overflow the system's capacity, leading to chaos! An attacker could remotely manipulate the system, potentially gaining control over the router, altering configurations, or executing arbitrary code. This could lead to a total breakdown of network security, putting all connected devices at risk. Imagine having someone at the helm, changing your network settings at will — not a pleasant thought!

Put simply

Think of this as a restaurant with a faulty reservation system — if a diner can tamper with the booking times, they might just push their dinner plans to the front of the queue, disrupting everything behind them. In this case, malicious input could overflow the system's capacity, leading to chaos! This vulnerability allows remote attackers to exploit the stack-based buffer overflow by manipulating the 'timeZone' parameter in the /goform/SetSysTimeCfg endpoint, resulting in unintended memory access and potential execution of malicious code.

What to do

An attacker could remotely manipulate the system, potentially gaining control over the router, altering configurations, or executing arbitrary code. This could lead to a total breakdown of network security, putting all connected devices at risk. Imagine having someone at the helm, changing your network settings at will — not a pleasant thought! To mitigate this risk, update the firmware of Tenda AC21 routers to the latest version immediately. Additionally, ensure that input validation measures are in place to check for malicious data. Regularly audit your network settings to spot any unusual configurations. 🛡️ You've got this! Stay vigilant, follow these steps, and secure your network like the hero you are! 💪✨

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.04209 · 90.9th percentile
Weaknesses
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer; CWE-121 · Stack-based Buffer Overflow
Published
2025-11-20T20:17Z
Affected products (1)
ProductVersionsFixed in
tenda/ac21_firmwareall versions—
References (9)
EPSS history
Timeline
  • 20 NOV 02:32Z
    Tenda AC21 SetSysTimeCfg stack-based overflow
    cvelistv5