CVE-2021-1616
Published: 23 September 2021
Summary
CVE-2021-1616 is a medium-severity Protection Mechanism Failure (CWE-693) vulnerability in Cisco Ios Xe. Its CVSS base score is 4.7 (Medium).
Operationally, ranked in the top 30.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-7083
Vulnerability details
A vulnerability in the H.323 application level gateway (ALG) used by the Network Address Translation (NAT) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass the ALG. This vulnerability is due to insufficient data validation…
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of traffic that is traversing the ALG. An attacker could exploit this vulnerability by sending crafted traffic to a targeted device. A successful exploit could allow the attacker to bypass the ALG and open connections that should not be allowed to a remote device located behind the ALG. Note: This vulnerability has been publicly discussed as NAT Slipstreaming.
- 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.
Implements a reliable, tamperproof protection mechanism whose completeness can be assured.
Procedures for training on protection mechanisms reduce the chance of protection mechanism failures being present or exploitable.
Documented procedures to implement assessment, authorization, and monitoring controls prevent these protection mechanisms from failing due to undefined processes.
Direct evaluation of whether controls produce desired security outcomes detects protection mechanism failures and enables remediation.
Requires assessment that protection mechanisms are correctly implemented and producing intended security outcomes.
The POA&M process ensures identified weaknesses in protection mechanisms are documented and scheduled for remediation, reducing the duration they remain exploitable.
Ongoing control assessments and analysis of monitoring data enable timely detection and response when protection mechanisms fail.
Impact analysis identifies changes that could weaken or disable existing protection mechanisms.