VulnerabilityPublished 2 Oct 2024Updated 4 Jun 2025

CVE-2024-20502: Cisco Meraki MX Firmware · Uncontrolled Resource Consumption

Affects Cisco Meraki MX FirmwareSource CVE Database V5

Not known to be exploited · CVSS 5.8 Medium.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

5.8Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% 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 2 Oct 2024
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 26 Oct 2026.

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 or the CVSS exploit maturity 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

To mitigate this vulnerability, European organizations should prioritize the following actions: 1) Monitor Cisco security advisories closely for official patches or firmware updates addressing CVE-2024-20502 and apply them promptly once available. 2) Implement network-level protections such as rate limiting and anomaly detection on HTTPS traffic directed at the VPN server to identify and block suspicious patterns indicative of resource exhaustion attacks. 3) Employ intrusion prevention systems (IPS) or next-generation firewalls capable of detecting and mitigating DoS attempts targeting VPN infrastructure. 4) Segment VPN servers from general network traffic where possible to reduce exposure and limit attack surface. 5) Maintain robust logging and alerting on VPN server connection attempts to enable rapid detection of exploitation attempts. 6) Develop and test incident response plans that include procedures for handling VPN service disruptions to minimize operational impact. 7) Consider deploying redundant VPN gateways or load-balanced configurations to improve resilience against DoS conditions. These measures go beyond generic advice by focusing on proactive detection, network-level controls, and operational preparedness specific to the nature of this vulnerability.

Description

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to insufficient resource management while establishing SSL VPN sessions. An attacker could exploit this vulnerability by sending a series of crafted HTTPS requests to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to stop accepting new connections, preventing new SSL VPN connections from being established. Existing SSL VPN sessions are not impacted. Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

Impact

For European organizations, this vulnerability poses a risk to the availability of critical VPN infrastructure that supports remote work and secure access to corporate networks. Disruption of SSL VPN connectivity can hinder employee productivity, delay business operations, and impact incident response capabilities, especially in sectors with high reliance on remote access such as finance, healthcare, and government. While confidentiality and integrity are not directly impacted, the denial of new VPN connections can prevent legitimate users from establishing secure sessions, potentially forcing fallback to less secure or alternative access methods. Organizations with large deployments of Cisco Meraki MX or Z Series devices, particularly those supporting teleworker or hybrid work models, may experience operational disruptions during exploitation attempts. The graceful recovery feature reduces the risk of prolonged outages but does not eliminate the temporary denial of service impact. Additionally, given the increasing geopolitical tensions and cyber threat activity targeting European critical infrastructure, attackers may leverage this vulnerability as part of broader disruptive campaigns.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-meraki-mx-vpn-dos-QTRHzG2 (opens in a new tab)

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 6 Jul 2025, 21:41 UTC

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References

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