Strix
26.1K

CVE-2020-3548

HIGHCVSS 7.5/10EPSS 0.81%

Last modified

CVE-2020-3548 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A vulnerability in the Transport Layer Security (TLS) protocol implementation of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient processing of incoming TLS traffic. An attacker could exploit this vulnerability by sending a series of crafted TLS packets to an affected device. EPSS estimates a 0.81% chance of exploitation in the next 30 days.

Description

A vulnerability in the Transport Layer Security (TLS) protocol implementation of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient processing of incoming TLS traffic. An attacker could exploit this vulnerability by sending a series of crafted TLS packets to an affected device. A successful exploit could allow the attacker to trigger a prolonged state of high CPU utilization. The affected device would still be operative, but response time and overall performance may be degraded.There are no workarounds that address this vulnerability.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
0.81%

52.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoEmail Security Appliance<= 13.5.1-277

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2020-3548?
A vulnerability in the Transport Layer Security (TLS) protocol implementation of Cisco&nbsp;AsyncOS software for Cisco&nbsp;Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to inefficient processing of incoming TLS traffic. An attacker could exploit this vulnerability by sending a series of crafted TLS packets to an affected device. A successful exploit could allow the attacker to trigger a prolonged state of high CPU utilization. The affected device would still be operative, but response time and overall performance may be degraded.There are no workarounds that address this vulnerability.
How severe is CVE-2020-3548?
CVE-2020-3548 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.81% probability of exploitation in the next 30 days.
How do I fix CVE-2020-3548?
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-2020-3548?

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

Scan your code now

Source: NVD / NIST