CVE-2025-20135
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-08-14

Last updated on: 2025-08-15

Assigner: Cisco Systems, Inc.

Description
A vulnerability in the DHCP client functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to exhaust available memory. This vulnerability is due to improper validation of incoming DHCP packets. An attacker could exploit this vulnerability by repeatedly sending crafted DHCPv4 packets to an affected device. A successful exploit could allow the attacker to exhaust available memory, which would affect availability of services and prevent new processes from starting, resulting in a Denial of Service (DoS) condition that would require a manual reboot. Note: On Cisco Secure FTD Software, this vulnerability does not affect management interfaces.
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Meta Information
Published
2025-08-14
Last Modified
2025-08-15
Generated
2026-05-06
AI Q&A
2025-08-14
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
cisco secure_firewall_threat_defense *
cisco secure_firewall_adaptive_security_appliance *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-401 The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the DHCP client functionality of Cisco Secure Firewall ASA and FTD Software. It occurs because the software improperly validates incoming DHCP packets. An unauthenticated attacker who is adjacent to the device can exploit this by sending specially crafted DHCPv4 packets repeatedly, causing the device to exhaust its available memory. This leads to a Denial of Service (DoS) condition requiring a manual reboot.


How can this vulnerability impact me? :

Exploiting this vulnerability can cause the affected Cisco firewall device to run out of memory, which disrupts the availability of services and prevents new processes from starting. This results in a Denial of Service (DoS) condition, potentially causing network downtime until the device is manually rebooted.


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