CVE-2025-20225VulnerabilityPublished 14 Aug 2025

CVE-2025-20225: Cisco IOS · Memory Leak

Affects Cisco IOSSource CVE Database V5

Not known to be exploited · CVSS 5.8 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

European organizations should prioritize the following mitigation steps: 1) Inventory and identify all Cisco IOS, IOS XE, ASA, and FTD devices running affected versions to assess exposure. 2) Monitor Cisco's official advisories and security bulletins for patches or updates addressing CVE-2025-20225 and apply them promptly once available. 3) Implement network-level protections such as access control lists (ACLs) or firewall rules to restrict incoming IKEv2 traffic to trusted IP addresses and networks, minimizing exposure to unauthenticated attackers. 4) Employ intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection capable of identifying malformed or suspicious IKEv2 packets to block exploitation attempts. 5) Regularly monitor device memory usage and system logs for signs of memory leaks or instability that could indicate exploitation attempts. 6) Plan for rapid incident response procedures including device reboot protocols to restore service if a DoS condition occurs. 7) Consider deploying redundant VPN gateways and failover mechanisms to maintain connectivity during device reloads or outages. 8) Harden network segmentation to isolate VPN infrastructure from general internet-facing services, reducing attack surface. These targeted measures go beyond generic advice by focusing on controlling attack vectors specific to IKEv2 and maintaining operational resilience in the face of potential DoS attacks.

Description

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) feature of Cisco IOS Software, IOS XE Software, Secure Firewall Adaptive Security Appliance (ASA) Software, and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition. This vulnerability is due to a lack of proper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. In the case of Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to cause the device to reload unexpectedly. In the case of Cisco ASA and FTD Software, a successful exploit could allow the attacker to partially exhaust system memory, causing system instability such as being unable to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from this condition.

Impact

For European organizations, this vulnerability poses a risk to network infrastructure stability and availability, especially for entities relying heavily on Cisco devices for VPN connectivity and firewall protection. Disruption of IKEv2 VPN sessions can lead to loss of secure remote access for employees, partners, and customers, impacting business continuity. Critical sectors such as finance, healthcare, government, and telecommunications, which often use Cisco ASA and FTD devices for perimeter security and VPN services, may experience operational interruptions. The forced device reloads on IOS and IOS XE devices can cause temporary network outages, affecting internal and external communications. Additionally, the inability to establish new VPN sessions due to memory exhaustion on ASA and FTD devices may expose organizations to increased risk during incident response or remote work scenarios. Although the vulnerability does not allow data compromise or unauthorized access directly, the availability impact can indirectly affect confidentiality and integrity by disrupting security monitoring and incident response capabilities. Given the medium severity and lack of required authentication or user interaction, the threat can be exploited by remote attackers with network access, increasing the risk in environments with exposed VPN endpoints or insufficient network segmentation.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ios-dos-DOESHWHy (opens in a new tab)

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 14 Aug 2025, 17:22 UTC

Technical details

References

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