{"id":64275,"date":"2025-08-24T00:11:14","date_gmt":"2025-08-24T00:11:14","guid":{"rendered":""},"modified":"2025-09-06T23:19:42","modified_gmt":"2025-09-07T05:19:42","slug":"cve-2025-20239-denial-of-service-vulnerability-in-cisco-ios-ios-xe-asa-and-ftd-software","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-20239-denial-of-service-vulnerability-in-cisco-ios-ios-xe-asa-and-ftd-software\/","title":{"rendered":"CVE-2025-20239: Denial of Service Vulnerability in Cisco IOS, IOS XE, ASA and FTD Software<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

This blog post is set to discuss the recently discovered vulnerability, CVE-2025-20239, which poses a significant threat to the Internet Key Exchange Version 2 (IKEv2) feature of various Cisco software. This vulnerability is particularly alarming due to its potential to allow an unauthenticated, remote attacker to cause a denial of service condition. As Cisco software<\/a> is widely utilized, this vulnerability has wide-ranging implications and requires immediate attention.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-20239
\nSeverity: High (8.6)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Potential system compromise<\/a> or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Cisco IOS Software | All versions prior<\/a> to the vendor patch
\nCisco IOS XE Software<\/a> | All versions prior to the vendor patch
\nCisco Secure Firewall ASA Software<\/a> | All versions prior to the vendor patch
\nCisco Secure Firewall FTD<\/a> Software | All versions prior to the vendor patch<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The CVE-2025-20239 vulnerability takes advantage of a flaw in the processing<\/a> of IKEv2 packets within the affected Cisco software. An attacker can craft specific IKEv2 packets and send them to the targeted device. These packets can trigger a memory<\/a> leak, leading to a denial of service condition. In the case of Cisco IOS and IOS XE Software, this could cause the device to unexpectedly reload, while in the case of Cisco ASA and FTD Software, it could lead to exhaustion of system memory<\/a>, causing system instability and the inability to establish new IKEv2 VPN sessions.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

While the exact methods will vary based on the attacker’s skill and the specific target, a conceptual example of an attack might look like this:<\/p>\n

POST \/IKEv2\/process HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/x.ikev2\n{ \"IKEv2_packet\": \"crafted_malicious_packet_data\" }<\/code><\/pre>\n
In this example, the attacker sends a crafted IKEv2 packet to the vulnerable<\/a> endpoint (“IKEv2\/process” in this example), which subsequently triggers the memory leak and denial of service condition.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview This blog post is set to discuss the recently discovered vulnerability, CVE-2025-20239, which poses a significant threat to the Internet Key Exchange Version 2 (IKEv2) feature of various Cisco software. This vulnerability is particularly alarming due to its potential to allow an unauthenticated, remote attacker to cause a denial of service condition. As Cisco […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[77,96],"product":[97],"attack_vector":[87],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-64275","post","type-post","status-publish","format-standard","hentry","category-uncategorized","vendor-apple","vendor-cisco","product-cisco-ios-xe","attack_vector-dos"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t