CVE-2023-20042

HIGHCVSS 8.6/10EPSS 0.68%

Last modified

CVE-2023-20042 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. EPSS estimates a 0.68% chance of exploitation in the next 30 days.

Description

A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. An attacker could exploit this vulnerability by sending crafted SSL/TLS traffic to an affected device, increasing the probability of session handler leaks. A successful exploit could allow the attacker to eventually deplete the available session handler pool, preventing new sessions from being established and causing a DoS condition.

Metrics

CVSS 3.1
8.6/10

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

EPSS Probability
0.68%

47.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoFirepower Threat Defense7.0.0
CiscoFirepower Threat Defense7.0.0.1
CiscoFirepower Threat Defense7.0.1
CiscoFirepower Threat Defense7.0.1.1
CiscoFirepower Threat Defense7.0.2
CiscoFirepower Threat Defense7.0.2.1
CiscoFirepower Threat Defense7.0.3
CiscoFirepower Threat Defense7.0.4
CiscoFirepower Threat Defense7.0.5
CiscoFirepower Threat Defense7.1.0
CiscoFirepower Threat Defense7.1.0.1
CiscoFirepower Threat Defense7.1.0.2
CiscoFirepower Threat Defense7.1.0.3
CiscoFirepower Threat Defense7.2.0
CiscoFirepower Threat Defense7.2.0.1
CiscoFirepower Threat Defense7.2.1
CiscoFirepower Threat Defense7.2.2
CiscoFirepower Threat Defense7.2.3
CiscoFirepower Threat Defense7.3.0
CiscoFirepower Threat Defense7.3.1
CiscoFirepower Threat Defense7.3.1.1
CiscoAdaptive Security Appliance Software9.16.1
CiscoAdaptive Security Appliance Software9.16.1.28
CiscoAdaptive Security Appliance Software9.16.2
CiscoAdaptive Security Appliance Software9.16.2.3
CiscoAdaptive Security Appliance Software9.16.2.7
CiscoAdaptive Security Appliance Software9.16.2.11
CiscoAdaptive Security Appliance Software9.16.2.13
CiscoAdaptive Security Appliance Software9.16.2.14
CiscoAdaptive Security Appliance Software9.16.3
CiscoAdaptive Security Appliance Software9.16.3.3
CiscoAdaptive Security Appliance Software9.16.3.14
CiscoAdaptive Security Appliance Software9.16.3.15
CiscoAdaptive Security Appliance Software9.16.3.19
CiscoAdaptive Security Appliance Software9.16.3.23
CiscoAdaptive Security Appliance Software9.16.4
CiscoAdaptive Security Appliance Software9.16.4.9
CiscoAdaptive Security Appliance Software9.17.1
CiscoAdaptive Security Appliance Software9.17.1.7
CiscoAdaptive Security Appliance Software9.17.1.9
CiscoAdaptive Security Appliance Software9.17.1.10
CiscoAdaptive Security Appliance Software9.17.1.11
CiscoAdaptive Security Appliance Software9.17.1.13
CiscoAdaptive Security Appliance Software9.17.1.15
CiscoAdaptive Security Appliance Software9.17.1.20
CiscoAdaptive Security Appliance Software9.18.1
CiscoAdaptive Security Appliance Software9.18.1.3
CiscoAdaptive Security Appliance Software9.18.2
CiscoAdaptive Security Appliance Software9.18.2.5
CiscoAdaptive Security Appliance Software9.18.2.7

Showing 50 of 51 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-20042?
A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. An attacker could exploit this vulnerability by sending crafted SSL/TLS traffic to an affected device, increasing the probability of session handler leaks. A successful exploit could allow the attacker to eventually deplete the available session handler pool, preventing new sessions from being established and causing a DoS condition.
How severe is CVE-2023-20042?
CVE-2023-20042 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 0.68% probability of exploitation in the next 30 days.
How do I fix CVE-2023-20042?
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-2023-20042?

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

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Source: NVD / NIST