CVE-2021-34793

高 8.6CVE-2021-34793 · 27/10/2021 公開 · 11/08/2026 更新

要点

CVE-2021-34793 は adaptive security appliance (cisco), secure firewall threat defense (cisco) に影響する深刻度「高」 (CVSS 8.6) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.59%（全脆弱性の 48.1% より高い）。
対処：9.8.4.40, 6.6.5, 6.7.0.3, 6.4.0.13 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
adaptive security appliance cisco	`< 9.8.4.40`	`9.8.4.40`
secure firewall threat defense cisco	`≥ 6.5.0, < 6.6.5≥ 6.7.0, < 6.7.0.3< 6.4.0.13`	`6.6.56.7.0.36.4.0.13`

概要

A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.