Cisco IOS XE Software Interface Queue Wedge Denial of Service Vulnerability
Priority LOW 32CWE-399Published · Updated
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-399 and the CVSS impact.
Summary
A vulnerability in the Layer 2 punt code of Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause a queue wedge on an interface that receives specific Layer 2 frames, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of certain Layer 2 frames. An attacker could exploit this vulnerability by sending specific Layer 2 frames on the segment the router is connected to. A successful exploit could allow the attacker to cause a queue wedge on the interface, resulting in a DoS condition.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0036 30th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Cisco | Cisco IOS XE Software | all versions | — | No fix listed | CNA |
- Cisco IOS XE Software VendorCisco Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 45
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:* | before 17.3.1 | Vulnerable | Cisco |
| cpe:2.3:h:cisco:1000_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1100-4g\/6g_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1100-4p_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1100-8p_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1100_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1101-4p_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1101_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1109-2p_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1109-4p_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
- cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:* Versions before 17.3.1 Vulnerable ·Cisco
- cpe:2.3:h:cisco:1000_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1100-4g\/6g_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1100-4p_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1100-8p_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1100_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1101-4p_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1101_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1109-2p_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1109-4p_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
Show 35 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:h:cisco:1109_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1111x-8p_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1111x_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:111x_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1120_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:1160_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4000_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4221_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4321_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4331_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4351_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4431_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4451-x_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4451_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:4461_integrated_services_router:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1000:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1000-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1001:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1001-hx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1001-hx_r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1001-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1001-x_r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1002:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1002-hx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1002-hx_r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1002-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1002-x_r:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1004:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1006:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1006-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1009-x:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1013:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1023:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:csr_1000v:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:isrv:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
- cpe:2.3:h:cisco:1109_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1111x-8p_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1111x_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:111x_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1120_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:1160_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4000_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4221_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4321_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4331_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4351_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4431_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4451-x_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4451_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:4461_integrated_services_router:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1000:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1000-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1001:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1001-hx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1001-hx_r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1001-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1001-x_r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1002:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1002-hx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1002-hx_r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1002-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1002-x_r:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1004:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1006:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1006-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1009-x:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1013:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1023:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:csr_1000v:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:isrv:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-1621
- 2026-10-03 Alias added: GHSA-7pgq-9248-43gw
References
More Cisco Ios Xe vulnerabilities
- TI-2023-06904 Cisco is providing an update for the ongoing investigation into observed exploitation of… KEVCVSS 3.1CRITICAL 10.0
- TI-2018-00122 Memory corruption in Cisco IOS and IOS XE KEVCVSS 3.1CRITICAL 9.8
- TI-2017-02977 Improper input validation in Cisco IOS and IOS XE Software KEVCVSS 3.1CRITICAL 9.8
- TI-2018-00135 Memory corruption in Cisco IOS, IOS XE, and IOS XR KEVCVSS 3.1HIGH 8.8
- TI-2017-04498 Memory corruption in Cisco IOS KEVCVSS 3.1HIGH 8.8
- TI-2017-04497 Memory corruption in Cisco IOS XE Software KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2021-1621 · CVE Program
- CVE-2021-1621 · NVD
- FIRST EPSS
- GHSA-7pgq-9248-43gw · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences