CVE-2021-34740: Cisco Aironet Access Points WLAN Control Protocol Packet Buffer Leak Denial of Service Vulnerability
Noroxi assessment
Priority: Monitor (action score 29/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.36% (FIRST EPSS).
- Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to the record, no fixed version is available yet.
Low priority for now. Update when a fix is released; follow the vendor's advisory.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
A vulnerability in the WLAN Control Protocol (WCP) implementation for Cisco Aironet Access Point (AP) software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect error handling when an affected device receives an unexpected 802.11 frame. An attacker could exploit this vulnerability by sending certain 802.11 frames over the wireless network to an interface on an affected AP. A successful exploit could allow the attacker to cause a packet buffer leak. This could eventually result in buffer allocation failures, which would trigger a reload of the affected device.
- Published
- Sep 22, 2021
- Updated
- Jun 16, 2026
- EPSS
- 0.3% · 29th percentile
- CWE
- CWE-401
Report tools
Action score
29
Monitor
Low priority for now.
- CVSS
- 29 / 40 · 7.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.4
- CNA · cisco
- 7.4
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| cisco | catalyst 9115 | cpe:2.3:h:cisco:catalyst_9115 |
| cisco | aironet access point software | cpe:2.3:o:cisco:aironet_access_point_software |
| cisco | 1100-4g\/6g integrated services router | cpe:2.3:h:cisco:1100-4g\/6g_integrated_services_router |
| cisco | 1100-4p integrated services router | cpe:2.3:h:cisco:1100-4p_integrated_services_router |
| cisco | 1100-8p integrated services router | cpe:2.3:h:cisco:1100-8p_integrated_services_router |
| cisco | 1100 integrated services router | cpe:2.3:h:cisco:1100_integrated_services_router |
| cisco | 1101-4p integrated services router | cpe:2.3:h:cisco:1101-4p_integrated_services_router |
| cisco | 1101 integrated services router | cpe:2.3:h:cisco:1101_integrated_services_router |
| cisco | 1109-2p integrated services router | cpe:2.3:h:cisco:1109-2p_integrated_services_router |
| cisco | 1109-4p integrated services router | cpe:2.3:h:cisco:1109-4p_integrated_services_router |
| cisco | 1109 integrated services router | cpe:2.3:h:cisco:1109_integrated_services_router |
| cisco | 1111x-8p integrated services router | cpe:2.3:h:cisco:1111x-8p_integrated_services_router |
and 59 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco aironet access point software8.10.0 and later · before 8.10.162.0
- cisco aironet access point software17.2
- cisco aironet access point software17.3
Versions reported by the vendor
Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.
Cisco Cisco Aironet Access Point Software
- n/aaffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-3831A vulnerability in the web-based GUI of Cisco Mobility Express 1800 Series Access Points could allow an unauthenticated, remote attacker to 41Plan
- CVE-2018-0234A vulnerability in the implementation of Point-to-Point Tunneling Protocol (PPTP) functionality in Cisco Aironet 1810, 1830, and 1850 Series35Monitor
- CVE-2015-6367Cisco Aironet 1800 devices with software 8.1(131.0) allow remote attackers to cause a denial of service (CPU consumption) by improperly esta32Monitor
Published before and after this one in the same product
- ← EarlierCVE-2021-1449Mar 24, 2021 · Cisco Access Point Software Arbitrary Code Execution Vulnerability26Monitor
- ← EarlierCVE-2021-1423Mar 24, 2021 · Cisco Aironet Access Points Arbitrary File Overwrite Vulnerability17Monitor
- Later →CVE-2022-20622Apr 15, 2022 · Cisco Embedded Wireless Controller with Catalyst Access Points IP Flood Denial of Service Vulnerability30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Adjacent
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-401 · Missing Release of Memory after Effective LifetimeCVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.