CONFERENCE Watch Now: Threat Detection & Incident Response (TDIR) Summit - Watch Event On-Demand
Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Email Security

Malicious Emails Can Crash Cisco Email Security Appliances

Cisco this week informed customers that its Email Security Appliance (ESA) product is affected by a high-severity denial of service (DoS) vulnerability that can be exploited using specially crafted emails.

Cisco this week informed customers that its Email Security Appliance (ESA) product is affected by a high-severity denial of service (DoS) vulnerability that can be exploited using specially crafted emails.

The flaw, tracked as CVE-2022-20653, affects the DNS-based Authentication of Named Entities (DANE) email verification component of Cisco AsyncOS Software for ESA. It can be exploited remotely without authentication.

The vulnerability is caused by insufficient error handling in DNS name resolution, Cisco said in its advisory.

“An attacker could exploit this vulnerability by sending specially formatted email messages that are processed by an affected device,” the company explained. “A successful exploit could allow the attacker to cause the device to become unreachable from management interfaces or to process additional email messages for a period of time until the device recovers, resulting in a DoS condition. Continued attacks could cause the device to become completely unavailable, resulting in a persistent DoS condition.”

While the vulnerability sounds serious, it’s worth noting that it only impacts devices that have the DANE feature enabled and downstream mail servers configured to send bounce messages. Cisco noted that the DANE feature is not enabled by default.

Patches and workarounds have been made available, and Cisco has advised customers to deploy them in order to prevent potential exploitation.

Cisco has credited several people working with Dutch government ICT services provider DICTU for reporting the security hole.

The networking giant says there is no evidence of malicious exploitation.

Advertisement. Scroll to continue reading.

Cisco this week also released two advisories that inform customers about medium-severity issues affecting Cisco RCM for Cisco StarOS software (DoS vulnerability), and Cisco Prime Infrastructure and Cisco Evolved Programmable Network Manager (XSS vulnerability).

Related: Cisco Patches Critical Vulnerabilities in Small Business RV Routers

Related: Over 70 Vulnerabilities Will Remain Unpatched in EOL Cisco Routers

Related: Cisco Patches Critical Vulnerability in Contact Center Products

Written By

Eduard Kovacs (@EduardKovacs) is a managing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this event as we dive into threat hunting tools and frameworks, and explore value of threat intelligence data in the defender’s security stack.

Register

Learn how integrating BAS and Automated Penetration Testing empowers security teams to quickly identify and validate threats, enabling prompt response and remediation.

Register

People on the Move

Jeremy Koppen has left Mandiant after 13 years to become the CISO of Equifax.

Engineering and technology solutions provider Amentum has appointed Max Shier as its CISO.

PAM provider Keeper Security has appointed Shane Barney as its Chief Information Security Officer.

More People On The Move

Expert Insights

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest cybersecurity news, threats, and expert insights. Unsubscribe at any time.