title: Cisco Email Security Appliance Filter Bypass Vulnerability
description: A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the configured user filters on an affected device. The vulnerability exists because the affected software insufficiently validates certain incoming SPF messages. An attacker could exploit this vulnerability by sending a custom SPF packet to an affected device. A successful exploit could allow the attacker to bypass the configured header filters, which could allow malicious content to pass through the device.
problem types: CWE-20
affected:
{
product: Cisco Email Security Appliance (ESA)
vendor: Cisco
versions:
lessThan: n/a, status: affected, version: unspecified, versionType: custom
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: LOW
integrityImpact: LOW
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
version: 3.0
]
exploits: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.