CVE-2021-34697
Published: 23 September 2021
Summary
CVE-2021-34697 is a medium-severity Improper Initialization (CWE-665) vulnerability in Cisco Ios Xe. Its CVSS base score is 5.8 (Medium).
Operationally, ranked in the top 35.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-21347
Vulnerability details
A vulnerability in the Protection Against Distributed Denial of Service Attacks feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct denial of service (DoS) attacks to or through the affected device. This vulnerability is due…
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to incorrect programming of the half-opened connections limit, TCP SYN flood limit, or TCP SYN cookie features when the features are configured in vulnerable releases of Cisco IOS XE Software. An attacker could exploit this vulnerability by attempting to flood traffic to or through the affected device. A successful exploit could allow the attacker to initiate a DoS attack to or through an affected device.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Ensures shared resources are explicitly initialized or cleared on allocation, preventing exposure of prior contents to new users or processes.
Mandates that every instance begins in a known (presumably clean) state, eliminating reliance on residual or uninitialized state left by prior executions.