Cisco Email Security Appliance および Cisco Secure Email and Web Manager 外部認証バイパスの脆弱性

Successful exploitation of CVE-2022-20798 grants an attacker complete control over the affected ESA or SMA device's web management interface. This includes the ability to modify configurations, access sensitive data (email content, user credentials), and potentially pivot to other systems on the network. Given the critical role ESAs and SMAs play in email security, a compromised device could lead to widespread data breaches, malware propagation, and disruption of email services. The impact is magnified if the device is used to manage multiple domains or has access to sensitive internal resources. This vulnerability shares similarities with other authentication bypass flaws where attackers can leverage misconfigured or vulnerable authentication protocols to gain elevated privileges.

Organizations heavily reliant on Cisco ESA and SMA for email security are particularly at risk. Environments using LDAP for authentication, especially those with exposed management interfaces, face the highest threat. Shared hosting environments where multiple customers share the same ESA/SMA instance are also vulnerable.

• linux / server:

journalctl -u smad | grep "LDAP authentication failed"

• generic web:

curl -I <esa_ip>/admin -v | grep Authentication: # Check for unexpected authentication headers

• cisco: Review Cisco device logs for failed LDAP authentication attempts and unusual login patterns. Examine LDAP configuration files for misconfigurations.

1. 2022-06-15Disclosure

   disclosure

1. 予約済み2021-11-02
2. 公開日2022-06-15
3. 更新日2024-11-01
4. EPSS 更新日2026-04-02

Due to the lack of a fixed version provided, immediate mitigation strategies are crucial. Administrators should temporarily disable LDAP authentication if possible, reverting to local authentication methods. Implement strict network segmentation to limit external access to the ESA/SMA management interface. Deploy a Web Application Firewall (WAF) with rules to block suspicious LDAP authentication attempts. Monitor logs for unusual login activity and authentication failures. Regularly review and harden LDAP configurations to prevent future exploitation. Continuously monitor Cisco's security advisories for a firmware update that addresses this vulnerability. After a fix is released, upgrade to the patched version and verify successful authentication by attempting a standard login and confirming LDAP authentication is functioning as expected.