MediumCVE-2024-20513

    Cisco Meraki Mx100 Firmware: Authorization Bypass Through User-Controlled Key (CVE-2024-20513)

    Published Sources: CVE.org

    What is affected, what to do

    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 for targeted users of the AnyConnect service on an affected device. This vulnerability is due to insufficient entropy for handlers that are used during SSL VPN session establishment.

    Update Cisco Meraki Mx65 Firmware to version 18.211.2, Cisco Meraki Mx64 Firmware to version 18.211.2, Cisco Meraki Z4c Firmware to version 18.211.2.

    Affected
    • Cisco Meraki Mx65 Firmware lt 17.6.0..18.211.2
    • Cisco Meraki Mx64 Firmware lt 17.6.0..18.211.2
    • Cisco Meraki Z4c Firmware lt 16.2..18.211.2
    • Cisco Meraki Z4 Firmware lt 16.2..18.211.2
    • Cisco Meraki Z3c Firmware lt 16.2..18.211.2
    • Cisco Meraki Z3 Firmware lt 16.2..18.211.2
    • Cisco Meraki Vmx Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx600 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx450 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx400 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx250 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx105 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx100 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx95 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx85 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx84 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx75 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx68w Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx68cw Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx68 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx67w Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx67c Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx67 Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx65w Firmware lt 16.2..18.211.2
    • Cisco Meraki Mx64w Firmware lt 16.2..18.211.2
    Fixed in
    • Cisco Meraki Mx65 Firmware 18.211.2
    • Cisco Meraki Mx64 Firmware 18.211.2
    • Cisco Meraki Z4c Firmware 18.211.2
    • Cisco Meraki Z4 Firmware 18.211.2
    • Cisco Meraki Z3c Firmware 18.211.2
    • Cisco Meraki Z3 Firmware 18.211.2
    • Cisco Meraki Vmx Firmware 18.211.2
    • Cisco Meraki Mx600 Firmware 18.211.2
    • Cisco Meraki Mx450 Firmware 18.211.2
    • Cisco Meraki Mx400 Firmware 18.211.2
    • Cisco Meraki Mx250 Firmware 18.211.2
    • Cisco Meraki Mx105 Firmware 18.211.2
    • Cisco Meraki Mx100 Firmware 18.211.2
    • Cisco Meraki Mx95 Firmware 18.211.2
    • Cisco Meraki Mx85 Firmware 18.211.2
    • Cisco Meraki Mx84 Firmware 18.211.2
    • Cisco Meraki Mx75 Firmware 18.211.2
    • Cisco Meraki Mx68w Firmware 18.211.2
    • Cisco Meraki Mx68cw Firmware 18.211.2
    • Cisco Meraki Mx68 Firmware 18.211.2
    • Cisco Meraki Mx67w Firmware 18.211.2
    • Cisco Meraki Mx67c Firmware 18.211.2
    • Cisco Meraki Mx67 Firmware 18.211.2
    • Cisco Meraki Mx65w Firmware 18.211.2
    • Cisco Meraki Mx64w Firmware 18.211.2

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    5.8

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: CVE.org

    0.4 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 39.2

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    47.69 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    5.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.8
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.4 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    39.2
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 2 October 2024
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-639

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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 for targeted users of the AnyConnect service on an affected device. This vulnerability is due to insufficient entropy for handlers that are used during SSL VPN session establishment. An unauthenticated attacker could exploit this vulnerability by brute forcing valid session handlers. An authenticated attacker could exploit this vulnerability by connecting to the AnyConnect VPN service of an affected device to retrieve a valid session handler and, based on that handler, predict further valid session handlers. The attacker would then send a crafted HTTPS request using the brute-forced or predicted session handler to the AnyConnect VPN server of the device. A successful exploit could allow the attacker to terminate targeted SSL VPN sessions, forcing remote users to initiate new VPN connections and reauthenticate.

    Source: NVD (NIST), cvelistv5

    Vendors and products

    Affected operating systems

    Affected operating systems
    Otherciscomeraki_mx100_firmware—
    Otherciscomeraki_mx105_firmware—
    Otherciscomeraki_mx250_firmware—
    Otherciscomeraki_mx400_firmware—
    Otherciscomeraki_mx450_firmware—
    Otherciscomeraki_mx600_firmware—
    Otherciscomeraki_mx64_firmware—
    Otherciscomeraki_mx64w_firmware—
    Otherciscomeraki_mx65_firmware—
    Otherciscomeraki_mx65w_firmware—
    Otherciscomeraki_mx67_firmware—
    Otherciscomeraki_mx67c_firmware—
    Otherciscomeraki_mx67w_firmware—
    Otherciscomeraki_mx68_firmware—
    Otherciscomeraki_mx68cw_firmware—
    Otherciscomeraki_mx68w_firmware—
    Otherciscomeraki_mx75_firmware—
    Otherciscomeraki_mx84_firmware—
    Otherciscomeraki_mx85_firmware—
    Otherciscomeraki_mx95_firmware—
    Otherciscomeraki_vmx_firmware—
    Otherciscomeraki_z3_firmware—
    Otherciscomeraki_z3c_firmware—
    Otherciscomeraki_z4_firmware—

    Weakness classes (CWE)

    • CWE-639Authorization Bypass Through User-Controlled Key

      Base

      The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

      Entry at MITRE CWE-639

    References & sources

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