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No exploitation reportedFix available

CVE-2021-1437

No exploitation reported by the sources we read.

  • Published2021-03-24
  • WeaknessCWE-275

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A vulnerability in the FlexConnect Upgrade feature of Cisco Aironet Series Access Points Software could allow an unauthenticated, remote attacker to obtain confidential information from an affected device. This vulnerability is due to an unrestricted Trivial File Transfer Protocol (TFTP) configuration. An attacker could exploit this vulnerability by sending a specific TFTP request to an affected device. A successful exploit could allow the attacker to download any file from the filesystem of the affected access point (AP).

Timeline

dates in UTC
  1. 2021-03-2420:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-1437?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-1437?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Cisco aironet access point softwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Cisco catalyst 9800 firmwareversion to verify
BranchAffectedFixed in
17.x≥ 17.1, < 17.3.317.3.3
Cisco wireless lan controller software
BranchAffectedFixed in
8.10≥ 8.10.112.0, < 8.10.142.08.10.142.0

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2024-11-08
  • OpenCVESSVC decisionnone—
  • CNACVSS 3.17.5read 2026-10-23
  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • CNAweakness (CWE)CWE-275read 2026-10-23
  • FIRST EPSSEPSS score1.5 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published
2021-03-24
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2021-1437?

A vulnerability in the FlexConnect Upgrade feature of Cisco Aironet Series Access Points Software could allow an unauthenticated, remote attacker to obtain confidential information from an affected device. This vulnerability is due to an unrestricted Trivial File Transfer Protocol (TFTP) configuration. An attacker could exploit this vulnerability by sending a specific TFTP request to an affected device. A successful exploit could allow the attacker to download any file from the filesystem of the affected access point (AP).

Is CVE-2021-1437 actively exploited?

Active exploitation of CVE-2021-1437 has not been confirmed. Its EPSS score was 1.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-1437?

CVE-2021-1437 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

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