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CVE-2019-1955

HIGHCVSS 7.5/10EPSS 1.41%

Last modified

CVE-2019-1955 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. The vulnerability is due to incomplete input and validation checking mechanisms for certain SPF messages that are sent to an affected device. EPSS estimates a 1.41% chance of exploitation in the next 30 days.

Description

A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. The vulnerability is due to incomplete input and validation checking mechanisms for certain SPF messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. A successful exploit could allow the attacker to bypass the header filters that are configured for the affected device, which could allow malicious content to pass through the device.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability
1.41%

69.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoEmail Security Appliance Firmware< 4.0mr1
CiscoEmail Security Appliance Firmware12.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2019-1955?
A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. The vulnerability is due to incomplete input and validation checking mechanisms for certain SPF messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. A successful exploit could allow the attacker to bypass the header filters that are configured for the affected device, which could allow malicious content to pass through the device.
How severe is CVE-2019-1955?
CVE-2019-1955 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.41% probability of exploitation in the next 30 days.
How do I fix CVE-2019-1955?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-1955?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST