CVE-2021-34769
CVE-2021-34769 is a high-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.
Key facts
- Severity: High (CVSS 3.x base score 8.6)
- CVSS v2: 7.8
- EPSS exploit prediction: 1% (68th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-415
- Affected product: Cisco Ios Xe
- Published:
- Last modified:
Description
Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to insufficient validation of CAPWAP packets. An attacker could exploit the vulnerabilities by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition.
Frequently asked questions
- What is CVE-2021-34769?
- Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to insufficient validation of CAPWAP packets. An attacker could exploit the vulnerabilities by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition.
- How severe is CVE-2021-34769?
- CVE-2021-34769 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2021-34769 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-34769?
- CVE-2021-34769 primarily affects Cisco Ios Xe. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-34769?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-34769 published?
- CVE-2021-34769 was published on 2021-09-23 and last updated on 2026-06-17.
References
Affected products (7)
- cpe:2.3:o:cisco:ios_xe:3.15.1xbs:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:3.15.2xbs:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:17.3.1:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:17.3.2:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:17.3.2a:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:17.4.1:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:17.5.1:*:*:*:*:*:*:*
More vulnerabilities in Cisco Ios Xe
- CVE-2025-20188 — Critical (CVSS 10.0): A vulnerability in the Out-of-Band Access Point (AP) Image Download, the Clean Air Spectral Recording, and the client…
- CVE-2023-20198 — Critical (CVSS 10.0): Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco…
- CVE-2021-34770 — Critical (CVSS 10.0): A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE…
- CVE-2019-12643 — Critical (CVSS 10.0): A vulnerability in the Cisco REST API virtual service container for Cisco IOS XE Software could allow an…
- CVE-2021-1619 — Critical (CVSS 9.8): A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could…
- CVE-2020-3227 — Critical (CVSS 9.8): A vulnerability in the authorization controls for the Cisco IOx application hosting infrastructure in Cisco IOS XE…
All CVEs affecting Cisco Ios Xe →
Other CWE-415 (Double Free) vulnerabilities
- CVE-2018-0101 — Critical (CVSS 10.0): A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA)…
- CVE-2026-8925 — Critical (CVSS 9.8): The curl logic that works with SASL authentication could end up cleaning up the GSASL context *twice* without clearing…
- CVE-2020-37239 — Critical (CVSS 9.8): libbabl 0.1.62 contains a broken double free detection vulnerability that allows attackers to bypass memory safety…
- CVE-2026-43011 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: net/x25: Fix potential double free of skb When…
- CVE-2026-31609 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid double-free in…
- CVE-2026-31608 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: server: avoid double-free in…