Cisco Adaptive Security Appliance Software IKEv2 Feature infinite loop

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.9$0-$5k0.00

Summaryinfo

A vulnerability was found in Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software. It has been rated as problematic. The impacted element is an unknown function of the component IKEv2 Feature. This manipulation causes infinite loop. This vulnerability appears as CVE-2025-20253. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software (version unknown). It has been declared as critical. Affected by this vulnerability is an unknown function of the component IKEv2 Feature. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect availability. The summary by CVE is:

A vulnerability in the IKEv2 feature of Cisco IOS Software, IOS XE Software, Secure Firewall ASA Software, and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is due to the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to cause an infinite loop that exhausts resources and could cause the device to reload.

The advisory is shared at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2025-20253 since 10/10/2024. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/17/2025). MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1838). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

  • Cisco IOS
  • Cisco IOS XE
  • Cisco ASA (Adaptive Security Appliance)
  • Cisco Secure Firewall Threat Defense

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.6
CNA Vector (cisco): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Infinite loop
CWE: CWE-835 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

10/10/2024 CVE reserved
08/14/2025 +308 days Advisory disclosed
08/14/2025 +0 days VulDB entry created
08/17/2025 +3 days VulDB entry last update

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-asa-ftd-ios-dos-DOESHWHy
Status: Confirmed

CVE: CVE-2025-20253 (🔒)
GCVE (CVE): GCVE-0-2025-20253
GCVE (VulDB): GCVE-100-320173
CERT Bund: WID-SEC-2025-1838 - Cisco IOS, XE, ASA, FTD: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 08/14/2025 19:43
Updated: 08/17/2025 07:29
Changes: 08/14/2025 19:43 (64), 08/17/2025 07:29 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Interested in the pricing of exploits?

See the underground prices here!