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Alpine: multiple docker packages: security update to 20.10.24-r0
high Tenable Cloud Security Plugin ID 404108
Description
There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:- 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 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. Two iptables rules serve to filter
incoming VXLAN datagrams with a VNI that corresponds to an encrypted network and discards unencrypted
datagrams. The rules are appended to the end of the INPUT filter chain, following any rules that have been
previously set by the system administrator. Administrator-set rules take precedence over the rules Moby
sets to discard unencrypted VXLAN datagrams, which can potentially admit unencrypted datagrams that should
have been discarded. The injection of arbitrary Ethernet frames can enable a Denial of Service attack. A
sophisticated attacker may be able to establish a UDP or TCP connection by way of the container’s outbound
gateway that would otherwise be blocked by a stateful firewall, or carry out other escalations beyond
simple injection by smuggling packets into the overlay network. 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. Close the VXLAN port (by default,
UDP port 4789) to incoming traffic at the Internet boundary to prevent all VXLAN packet injection, and/or
ensure that the `xt_u32` kernel module is available on all nodes of the Swarm cluster. (CVE-2023-28840)
- 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. An
iptables rule designates outgoing VXLAN datagrams with a VNI that corresponds to an encrypted overlay
network for IPsec encapsulation. Encrypted overlay networks on affected platforms silently transmit
unencrypted data. As a result, `overlay` networks may appear to be functional, passing traffic as
expected, but without any of the expected confidentiality or data integrity guarantees. It is possible for
an attacker sitting in a trusted position on the network to read all of the application traffic that is
moving across the overlay network, resulting in unexpected secrets or user data disclosure. Thus, because
many database protocols, internal APIs, etc. are not protected by a second layer of encryption, a user may
use Swarm encrypted overlay networks to provide confidentiality, which due to this vulnerability this is
no longer guaranteed. 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. Close the VXLAN port (by default, UDP port 4789) to outgoing traffic at the
Internet boundary in order to prevent unintentionally leaking unencrypted traffic over the Internet,
and/or ensure that the `xt_u32` kernel module is available on all nodes of the Swarm cluster.
(CVE-2023-28841)
- 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.
(CVE-2023-28842)
See Also
https://security.alpinelinux.org/vuln/CVE-2023-28840
Plugin Details
Severity: High
ID: 404108
Version: Revision 1.25
Type: Local
Published: 10/31/2023
Updated: 7/2/2026
Supported Sensors: Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security
Risk Information
VPR
Risk Factor: Medium
Score: 4.8
Percentile: 57.62
CVSS v2
Risk Factor: High
Base Score: 7.1
Temporal Score: 5.6
Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:C/A:C
CVSS Score Source: CVE-2023-28840
CVSS v3
Risk Factor: High
Base Score: 8.7
Temporal Score: 7.8
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:H
Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C
Vulnerability Information
Exploit Available: true
Exploit Ease: Exploits are available
Vulnerability Publication Date: 4/4/2023