Used in attacks· fix by 2021-11-17Not scored yet
Tenda AC11 Router
CVE-2021-31755
Tenda AC11 devices contain a stack buffer overflow vulnerability in /goform/setmac which allows attackers to execute code via a crafted post request.
What this means for your business
- It affects Tenda AC11 Router. It matters if your company, or a supplier that handles your data, runs it.
- Attackers are already using it. CISA added it to its list of flaws used in real attacks on 3 November 2021.
- FIRST's prediction model gives it a 87% chance of attack attempts being seen in the next 30 days, ranking above 99% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Tenda AC11 Router.
- 2If you do, follow CISA's required action below. No patch reference has been published yet.
- 3Treat it as urgent. US federal agencies must fix it by 17 November 2021. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
- 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Required action
Apply updates per vendor instructions.
CISA’s wording, unedited.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2021-11-03
- Added to KEV
- 2021-11-03
- Remediation due
- 2021-11-17
- Sources
- CISA KEV