CVE-2021-4234
Published: 06 July 2022
Summary
CVE-2021-4234 is a high-severity Network Amplification (CWE-406) vulnerability in Openvpn Openvpn Access Server. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 39.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-34091
Vulnerability details
OpenVPN Access Server 2.10 and prior versions are susceptible to resending multiple packets in a response to a reset packet sent from the client which the client again does not respond to, resulting in a limited amplification attack.
- 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.
Limits attacker success in sustaining network amplification DoS against the primary by providing a ready alternate processing capability.
Provides continuity when primary telecom is disrupted by insufficient control of network message volume or amplification.
Network-volume amplification against one channel can be bypassed via the pre-established alternate path.
Implements network message volume controls to block amplification DoS vectors.