What is CVE-2024-29018?A high-severity flaw in Moby, explained.
CVE-2024-29018 is a high-severity flaw (CVSS 7.5) in Moby from Mobyproject, published on 20 March 2024. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 0.8%. If you run an affected version, plan in the vendor’s fix.
Published 20 March 2024. Record last updated 17 June 2026. We keep this page's data up to date.
What is CVE-2024-29018? In plain terms.
It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data.
Moby is an open source container framework that is a key component of Docker Engine, Docker Desktop, and other distributions of container tooling or runtimes. Moby's networking implementation allows for many networks, each with their own IP address range and gateway, to be defined. This feature is frequently referred to as custom networks, as each network can have a different driver, set of parameters and thus behaviors. When creating a network, the `--internal` flag is used to designate a network as _internal_. The `internal` attribute in a docker-compose.yml file may also be used to mark a network _internal_, and other API clients may specify the `internal` parameter as well.
When containers with networking are created, they are assigned unique network interfaces and IP addresses. The host serves as a router for non-internal networks, with a gateway IP that provides SNAT/DNAT to/from container IPs.
Containers on an internal network may communicate between each other, but are precluded from communicating with any networks the host has access to (LAN or WAN) as no default route is configured, and firewall rules are set up to drop all outgoing traffic. Communication with the gateway IP address (and thus appropriately configured host services) is possible, and the host may communicate with any container IP directly.
In addition to configuring the Linux kernel's various networking features to enable container networking, `dockerd` directly provides some services to container networks. Principal among these is serving as a resolver, enabling service discovery, and resolution of names from an upstream resolver.
When a DNS request for a name that does not correspond to a container is received, the request is forwarded to the configured upstream resolver. This request is made from the container's network namespace: the level of access and routing of traffic is the same as if the request was made by the container itself.
As a consequence of this design, containers solely attached to an internal network will be unable to resolve names using the upstream resolver, as the container itself is unable to communicate with that nameserver. Only the names of containers also attached to the internal network are able to be resolved.
Many systems run a local forwarding DNS resolver. As the host and any containers have separate loopback devices, a consequence of the design described above is that containers are unable to resolve names from the host's configured resolver, as they cannot reach these addresses on the host loopback device. To bridge this gap, and to allow containers to properly resolve names even when a local forwarding resolver is used on a loopback address, `dockerd` detects this scenario and instead forward DNS requests from the host namework namespace. The loopback resolver then forwards the requests to its configured upstream resolvers, as expected.
Because `dockerd` forwards DNS requests to the host loopback device, bypassing the container network namespace's normal routing semantics entirely, internal networks can unexpectedly forward DNS requests to an external nameserver. By registering a domain for which they control the authoritative nameservers, an attacker could arrange for a compromised container to exfiltrate data by encoding it in DNS queries that will eventually be answered by their nameservers.
Docker Desktop is not affected, as Docker Desktop always runs an internal resolver on a RFC 1918 address.
Moby releases 26.0.0, 25.0.4, and 23.0.11 are patched to prevent forwarding any DNS requests from internal networks. As a workaround, run containers intended to be solely attached to internal networks with a custom upstream address, which will force all upstream DNS queries to be resolved from the container's network namespace.
What kind of flaw is it?
- CWE-669Incorrect Resource Transfer Between Spheres
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAnywhere on the internet
- How hard it is to pull offEasy: no special conditions
- Login needed firstNo login needed
- Does someone have to clickNo, nobody has to do anything
- What an attacker getsCan read data
Severity vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Is CVE-2024-29018 being exploited? Not that we know of.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.8%. That can change at any time, which is why we keep watching.
Timeline
- Published
- Record last updated
CVE-2024-29018 scores 48. Action: Plan remediation.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isSmaller factor
- Threat activity around itSmaller factor
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2024-29018 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2024-29018? One product.
The published record lists 1 product from 1 vendor. Versions are shown as published: "before 23.0.11" means every version up to, but not including, 23.0.11. If you run one of these, check your version, then go to the fix below.
- Application
Moby
by Mobyproject
Affected versionsbefore 23.0.1124.0.0 to before 25.0.526.0.0-rc126.0.0-rc226.0.0-rc3
How do I fix CVE-2024-29018? Four steps.
- Check whether you run itCompare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
- Apply the vendor’s fixInstall the update named in the vendor’s advisory. We’ve put the advisory first in the list.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Keep an eye on itTrack the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.
Does CVE-2024-29018 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
Free plan, no card needed. Nothing to install.
1 new flaw affects software Acme tracks
Moby is an open source container framework that is a key component of Docker Engine, Docker Desktop, and other distributions of container tooling or runtimes...
- Matched to
- Moby on Acme's software list
- What to do
- Plan in the vendor’s update
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2024-29018 is a high-severity flaw in Moby from Mobyproject, published on 20 March 2024. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data.
It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2024-29018 is 48 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.8%. That can change at any time, which is why we keep watching.
For Moby from Mobyproject: before 23.0.11, 24.0.0 to before 25.0.5, 26.0.0-rc1, 26.0.0-rc2, 26.0.0-rc3.
Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.