MediumCVE-2023-28842

    moby/moby's dockerd daemon encrypted overlay network with a single endpoint is unauthenticated (CVE-2023-28842)

    Published Sources: BSI, CVE.org, OSV

    What is affected, what to do

    Moby) is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (`dockerd`), which is developed as moby/moby is commonly referred to as *Docker*.

    Update moby to version 20.10.24, ECS to version 3.8.1.0.

    Affected
    • Moby gte 1.12.0, < 20.10.24..*

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

    Metrics

    6.8

    Priority

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

    Source: NVD, CVSS v3

    6.8

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: BSI, CVE.org, OSV

    1.4 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 73.1

    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
    79.15 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
    6.8 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
    6.8
    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
    1.4 %
    Moderate — model estimates 1-10% 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
    73.1
    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
    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-420, CWE-636

    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

    Moby) is an open source container framework developed by Docker Inc. that is distributed as Docker, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (`dockerd`), which is developed as moby/moby is commonly referred to as *Docker*. Swarm Mode, which is compiled in and delivered by default in `dockerd` and is thus present in most major Moby downstreams, is a simple, built-in container orchestrator that is implemented through a combination of SwarmKit and supporting network code. The `overlay` network driver is a core feature of Swarm Mode, providing isolated virtual LANs that allow communication between containers and services across the cluster. This driver is an implementation/user of VXLAN, which encapsulates link-layer (Ethernet) frames in UDP datagrams that tag the frame with the VXLAN metadata, including a VXLAN Network ID (VNI) that identifies the originating overlay network. In addition, the overlay network driver supports an optional, off-by-default encrypted mode, which is especially useful when VXLAN packets traverses an untrusted network between nodes. Encrypted overlay networks function by encapsulating the VXLAN datagrams through the use of the IPsec Encapsulating Security Payload protocol in Transport mode. By deploying IPSec encapsulation, encrypted overlay networks gain the additional properties of source authentication through cryptographic proof, data integrity through check-summing, and confidentiality through encryption. When setting an endpoint up on an encrypted overlay network, Moby installs three iptables (Linux kernel firewall) rules that enforce both incoming and outgoing IPSec. These rules rely on the `u32` iptables extension provided by the `xt_u32` kernel module to directly filter on a VXLAN packet's VNI field, so that IPSec guarantees can be enforced on encrypted overlay networks without interfering with other overlay networks or other users of VXLAN. The `overlay` driver dynamically and lazily defines the kernel configuration for the VXLAN network on each node as containers are attached and detached. Routes and encryption parameters are only defined for destination nodes that participate in the network. The iptables rules that prevent encrypted overlay networks from accepting unencrypted packets are not created until a peer is available with which to communicate. Encrypted overlay networks silently accept cleartext VXLAN datagrams that are tagged with the VNI of an encrypted overlay network. As a result, it is possible to inject arbitrary Ethernet frames into the encrypted overlay network by encapsulating them in VXLAN datagrams. The implications of this can be quite dire, and GHSA-vwm3-crmr-xfxw should be referenced for a deeper exploration. Patches are available in Moby releases 23.0.3, and 20.10.24. As Mirantis Container Runtime's 20.10 releases are numbered differently, users of that platform should update to 20.10.16. Some workarounds are available. In multi-node clusters, deploy a global ‘pause’ container for each encrypted overlay network, on every node. For a single-node cluster, do not use overlay networks of any sort. Bridge networks provide the same connectivity on a single node and have no multi-node features. The Swarm ingress feature is implemented using an overlay network, but can be disabled by publishing ports in `host` mode instead of `ingress` mode (allowing the use of an external load balancer), and removing the `ingress` network. If encrypted overlay networks are in exclusive use, block UDP port 4789 from traffic that has not been validated by IPSec.

    Source: BSI CSAF, BSI WID Portal, cvelistv5, OSV (Open Source Vulnerabilities), NVD (NIST)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    mobymoby
    • ≥ 1.12.0, < 20.10.24
    • —
    mobyprojectmoby
    • 1.12.0 – < 20.10.24
    • 23.0.0 – < 23.0.3
    • 20.10.24
    • 23.0.3
    DellECS
    • < 3.8.1.0
    • 3.8.1.0
    gogithub.com/docker/docker
    • 1.12.0
    • 23.0.0
    • —
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-420Unprotected Alternate Channel

      Base

      The product protects a primary channel, but it does not use the same level of protection for an alternate channel.

      Entry at MITRE CWE-420

    • CWE-636Not Failing Securely ('Failing Open')

      Class

      When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.

      Entry at MITRE CWE-636

    References & sources

    • github.commoby/moby/security/advisories/GHSA-6wrf-mxfj-pf5padvisory, x_refsource_CONFIRM, Mitigation, Vendor advisory
    • NVD (NIST)vuln/detail/CVE-2023-28842advisory
    • github.commoby/libnetwork/security/advisories/GHSA-gvm4-2qqg-m333web, x_refsource_MISC, Vendor advisory
    • github.commoby/moby/security/advisories/GHSA-232p-vwff-86mpweb, x_refsource_MISC, Not applicable
    • github.commoby/moby/security/advisories/GHSA-33pg-m6jh-5237web, x_refsource_MISC, Not applicable
    • github.commoby/moby/security/advisories/GHSA-vwm3-crmr-xfxwweb, x_refsource_MISC, Vendor advisory
    • lists.fedoraproject.orgarchives/list/package-announce@lists.fedoraproject.org/message/…
    • lists.fedoraproject.orgarchives/list/package-announce@lists.fedoraproject.org/message/…
    • lists.fedoraproject.orgarchives/list/package-announce@lists.fedoraproject.org/message/…
    • github.commoby/mobypackage
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