Vulnerability · Published Nov 4, 2021 · Assigned by cisco

CVE-2021-34741Cisco Email Security Appliance Denial of Service Vulnerability

High 7.5

In plain English

A high-severity resource allocation without limits in Cisco Email Security Appliance (ESA) from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 70% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)1.3%top 29.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

A vulnerability in the email scanning algorithm of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to perform a denial of service (DoS) attack against an affected device. This vulnerability is due to insufficient input validation of incoming emails. An attacker could exploit this vulnerability by sending a crafted email through Cisco ESA. A successful exploit could allow the attacker to exhaust all the available CPU resources on an affected device for an extended period of time, preventing other emails from being processed and resulting in a DoS condition.

Affected products (as reported)

Vendor	Product	Versions
Cisco	Cisco Email Security Appliance (ESA)	n/a

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

20211103 Cisco Email Security Appliance Denial of Service Vulnerability vendor-advisory, x_refsource_CISCO