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CVE-2021-34741

HIGHCVSS 7.5/10EPSS 1.25%

Last modified

CVE-2021-34741 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 1.25% chance of exploitation in the next 30 days.

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.

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
1.25%

65.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoAsyncos< 13.0.4
CiscoAsyncos13.5.3-010
CiscoAsyncos13.7.0-093

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-34741?
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.
How severe is CVE-2021-34741?
CVE-2021-34741 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.25% probability of exploitation in the next 30 days.
How do I fix CVE-2021-34741?
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-2021-34741?

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

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Source: NVD / NIST