Cisco IOS XE SD-WAN Software Buffer Overflow Vulnerability
Priority MEDIUM 54CWE-120Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
A vulnerability in the vDaemon process in Cisco IOS XE SD-WAN Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected device. This vulnerability is due to insufficient bounds checking when an affected device processes traffic. An attacker could exploit this vulnerability by sending crafted traffic to the device. A successful exploit could allow the attacker to cause a buffer overflow and possibly execute arbitrary commands with root-level privileges, or cause the device to reload, which could result in a denial of service condition.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02629 85th 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
- Yes
- Technical impact
- Total
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 SD-WAN Software | all versions | — | No fix listed | CNA |
- Cisco IOS XE SD-WAN Software VendorCisco Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 49
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:cisco:ios_xe_sd-wan:-:*:*:*:*:*:*:* | not specified by NVD | 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_sd-wan:-:*:*:*:*:*:*:* Versions not specified by NVD 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 39 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:422_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-esp100:-:*:*:*:*:*:*:* | 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_1000_series:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1000_series_route_processor_\(rp2\):-:*:*:*:*:*:*:* | not specified by NVD | Running on | Cisco |
| cpe:2.3:h:cisco:asr_1000_series_route_processor_\(rp3\):-:*:*:*:*:*:*:* | 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: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:422_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-esp100:-:*:*:*:*:*:*:* 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_1000_series:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1000_series_route_processor_\(rp2\):-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Cisco
- cpe:2.3:h:cisco:asr_1000_series_route_processor_\(rp3\):-:*:*:*:*:*:*:* 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
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-34727
- 2026-10-03 Alias added: GHSA-rxw2-fh82-mfcc
References
More Cisco Ios Xe Sd-wan vulnerabilities
- TI-2025-14647 Stack-based buffer overflow in Cisco IOS KEVCVSS 3.1HIGH 7.7
- TI-2021-01110 Cisco IOS XE SD-WAN Software Parameter Injection Vulnerabilities CVSS 3.1MEDIUM 6.7
- TI-2020-02926 Cisco SD-WAN Solution Software Buffer Overflow Vulnerability CVSS 3.1CRITICAL 9.8
- TI-2021-01028 Cisco SD-WAN Buffer Overflow Vulnerabilities CVSS 3.1CRITICAL 9.8
- TI-2021-01027 Cisco SD-WAN Buffer Overflow Vulnerabilities CVSS 3.1CRITICAL 9.8
- TI-2021-01341 Cisco IOS XE Software NETCONF and RESTCONF Authentication Bypass Vulnerability CVSS 3.1CRITICAL 9.8
Sources
- CVE-2021-34727 · CVE Program
- CVE-2021-34727 · NVD
- FIRST EPSS
- GHSA-rxw2-fh82-mfcc · 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