CVE-2023-25809

runc is a CLI tool for spawning and running containers according to the OCI specification. In affected versions it was found that rootless runc makes /sys/fs/cgroup writable in following conditons: 1. when runc is executed inside the user namespace, and the config.json does not specify the cgroup namespace to be unshared (e.g.., (docker|podman|nerdctl) run --cgroupns=host, with Rootless Docker/Podman/nerdctl) or 2. when runc is executed outside the user namespace, and /sys is mounted with rbind, ro (e.g., runc spec --rootless; this condition is very rare). A container may gain the write access to user-owned cgroup hierarchy /sys/fs/cgroup/user.slice/... on the host . Other users's cgroup hierarchies are not affected. Users are advised to upgrade to version 1.1.5. Users unable to upgrade may unshare the cgroup namespace ((docker|podman|nerdctl) run --cgroupns=private). This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts. or add /sys/fs/cgroup to maskedPaths.

runc is a CLI tool for spawning and running containers according to the OCI specification. In affected versions it was found that rootless runc makes /sys/fs/cgroup writable in following conditons: 1. when runc is executed inside the user namespace, and the config.json does not specify the cgroup namespace to be unshared (e.g.., (docker|podman|nerdctl) run --cgroupns=host, with Rootless Docker/Podman/nerdctl) or 2. when runc is executed outside the user namespace, and /sys is mounted with rbind, ro (e.g., runc spec --rootless; this condition is very rare). A container may gain the write access to user-owned cgroup hierarchy /sys/fs/cgroup/user.slice/... on the host . Other users's cgroup hierarchies are not affected. Users are advised to upgrade to version 1.1.5. Users unable to upgrade may unshare the cgroup namespace ((docker|podman|nerdctl) run --cgroupns=private). This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts. or add /sys/fs/cgroup to maskedPaths.

Impact

It was found that rootless runc makes /sys/fs/cgroup writable in following conditons:

1. when runc is executed inside the user namespace, and the config.json does not specify the cgroup namespace to be unshared (e.g.., (docker|podman|nerdctl) run --cgroupns=host, with Rootless Docker/Podman/nerdctl)
2. or, when runc is executed outside the user namespace, and /sys is mounted with rbind, ro (e.g., runc spec --rootless; this condition is very rare)

A container may gain the write access to user-owned cgroup hierarchy /sys/fs/cgroup/user.slice/... on the host . Other users's cgroup hierarchies are not affected.

Patches

v1.1.5 (planned)

Workarounds

• Condition 1: Unshare the cgroup namespace ((docker|podman|nerdctl) run --cgroupns=private). This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts.
• Condition 2 (very rare): add /sys/fs/cgroup to maskedPaths

runc is a CLI tool for spawning and running containers according to the OCI specification.

Security Fix(es):

runc is a CLI tool for spawning and running containers according to the OCI specification. In affected versions it was found that rootless runc makes /sys/fs/cgroup writable in following conditons: 1. when runc is executed inside the user namespace, and the config.json does not specify the cgroup namespace to be unshared (e.g.., (docker|podman|nerdctl) run --cgroupns=host, with Rootless Docker/Podman/nerdctl) or 2. when runc is executed outside the user namespace, and /sys is mounted with rbind, ro (e.g., runc spec --rootless; this condition is very rare). A container may gain the write access to user-owned cgroup hierarchy /sys/fs/cgroup/user.slice/... on the host . Other users's cgroup hierarchies are not affected. Users are advised to upgrade to version 1.1.5. Users unable to upgrade may unshare the cgroup namespace ((docker|podman|nerdctl) run --cgroupns=private). This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts. or add /sys/fs/cgroup to maskedPaths.(CVE-2023-25809)

runc is a CLI tool for spawning and running containers according to the OCI specification. It was found that AppArmor can be bypassed when /proc inside the container is symlinked with a specific mount configuration. This issue has been fixed in runc version 1.1.5, by prohibiting symlinked /proc. See PR #3785 for details. users are advised to upgrade. Users unable to upgrade should avoid using an untrusted container image.(CVE-2023-28642)

The container-tools module contains tools for working with containers, notably podman, buildah, skopeo, and runc.

Security Fix(es):

• go-yaml: Improve heuristics preventing CPU/memory abuse by parsing malicious or large YAML documents (CVE-2022-3064)

• golang: html/template: improper handling of JavaScript whitespace (CVE-2023-24540)

• net/http, golang.org/x/net/http2: avoid quadratic complexity in HPACK decoding (CVE-2022-41723)

• golang: crypto/tls: large handshake records may cause panics (CVE-2022-41724)

• golang: net/http, mime/multipart: denial of service from excessive resource consumption (CVE-2022-41725)

• golang.org/x/net/html: Cross site scripting (CVE-2023-3978)

• golang: net/http, net/textproto: denial of service from excessive memory allocation (CVE-2023-24534)

• golang: net/http, net/textproto, mime/multipart: denial of service from excessive resource consumption (CVE-2023-24536)

• golang: go/parser: Infinite loop in parsing (CVE-2023-24537)

• golang: html/template: backticks not treated as string delimiters (CVE-2023-24538)

• golang: html/template: improper sanitization of CSS values (CVE-2023-24539)

• runc: Rootless runc makes /sys/fs/cgroup writable (CVE-2023-25809)

• runc: volume mount race condition (regression of CVE-2019-19921) (CVE-2023-27561)

• runc: AppArmor can be bypassed when /proc inside the container is symlinked with a specific mount configuration (CVE-2023-28642)

• golang: html/template: improper handling of empty HTML attributes (CVE-2023-29400)

• golang: net/http: insufficient sanitization of Host header (CVE-2023-29406)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.9 Release Notes linked from the References section.

The container-tools module contains tools for working with containers, notably podman, buildah, skopeo, and runc.

Security Fix(es):

• go-yaml: Improve heuristics preventing CPU/memory abuse by parsing malicious or large YAML documents (CVE-2022-3064)

• golang: html/template: improper handling of JavaScript whitespace (CVE-2023-24540)

• net/http, golang.org/x/net/http2: avoid quadratic complexity in HPACK decoding (CVE-2022-41723)

• golang: crypto/tls: large handshake records may cause panics (CVE-2022-41724)

• golang: net/http, mime/multipart: denial of service from excessive resource consumption (CVE-2022-41725)

• golang.org/x/net/html: Cross site scripting (CVE-2023-3978)

• golang: net/http, net/textproto: denial of service from excessive memory allocation (CVE-2023-24534)

• golang: net/http, net/textproto, mime/multipart: denial of service from excessive resource consumption (CVE-2023-24536)

• golang: go/parser: Infinite loop in parsing (CVE-2023-24537)

• golang: html/template: backticks not treated as string delimiters (CVE-2023-24538)

• golang: html/template: improper sanitization of CSS values (CVE-2023-24539)

• containerd: Supplementary groups are not set up properly (CVE-2023-25173)

• runc: Rootless runc makes /sys/fs/cgroup writable (CVE-2023-25809)

• runc: volume mount race condition (regression of CVE-2019-19921) (CVE-2023-27561)

• runc: AppArmor can be bypassed when /proc inside the container is symlinked with a specific mount configuration (CVE-2023-28642)

• golang: html/template: improper handling of empty HTML attributes (CVE-2023-29400)

• golang: net/http: insufficient sanitization of Host header (CVE-2023-29406)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.9 Release Notes linked from the References section.

runc is a CLI tool for spawning and running containers according to the OCI specification. In affected versions it was found that rootless runc makes /sys/fs/cgroup writable in following conditons: 1. when runc is executed inside the user namespace, and the config.json does not specify the cgroup namespace to be unshared (e.g.., (docker|podman|nerdctl) run --cgroupns=host, with Rootless Docker/Podman/nerdctl) or 2. when runc is executed outside the user namespace, and /sys is mounted with rbind, ro (e.g., runc spec --rootless; this condition is very rare). A container may gain the write access to user-owned cgroup hierarchy /sys/fs/cgroup/user.slice/... on the host . Other users's cgroup hierarchies are not affected. Users are advised to upgrade to version 1.1.5. Users unable to upgrade may unshare the cgroup namespace ((docker|podman|nerdctl) run --cgroupns=private). This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts. or add /sys/fs/cgroup to maskedPaths.

The runC tool is a lightweight, portable implementation of the Open Container Format (OCF) that provides container runtime.

Security Fix(es):

• golang: crypto/tls: large handshake records may cause panics (CVE-2022-41724)
• runc: Rootless runc makes /sys/fs/cgroup writable (CVE-2023-25809)
• runc: volume mount race condition (regression of CVE-2019-19921) (CVE-2023-27561)
• runc: AppArmor can be bypassed when /proc inside the container is symlinked with a specific mount configuration (CVE-2023-28642)
• runc: integer overflow in netlink bytemsg length field allows attacker to override netlink-based container configuration (CVE-2021-43784)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

The container-tools module contains tools for working with containers, notably podman, buildah, skopeo, and runc.

Security Fix(es):

• go-yaml: Improve heuristics preventing CPU/memory abuse by parsing malicious or large YAML documents (CVE-2022-3064)
• golang: html/template: improper handling of JavaScript whitespace (CVE-2023-24540)
• net/http, golang.org/x/net/http2: avoid quadratic complexity in HPACK decoding (CVE-2022-41723)
• golang: crypto/tls: large handshake records may cause panics (CVE-2022-41724)
• golang: net/http, mime/multipart: denial of service from excessive resource consumption (CVE-2022-41725)
• golang.org/x/net/html: Cross site scripting (CVE-2023-3978)
• golang: net/http, net/textproto: denial of service from excessive memory allocation (CVE-2023-24534)
• golang: net/http, net/textproto, mime/multipart: denial of service from excessive resource consumption (CVE-2023-24536)
• golang: go/parser: Infinite loop in parsing (CVE-2023-24537)
• golang: html/template: backticks not treated as string delimiters (CVE-2023-24538)
• golang: html/template: improper sanitization of CSS values (CVE-2023-24539)
• runc: Rootless runc makes /sys/fs/cgroup writable (CVE-2023-25809)
• runc: volume mount race condition (regression of CVE-2019-19921) (CVE-2023-27561)
• runc: AppArmor can be bypassed when /proc inside the container is symlinked with a specific mount configuration (CVE-2023-28642)
• golang: html/template: improper handling of empty HTML attributes (CVE-2023-29400)
• golang: net/http: insufficient sanitization of Host header (CVE-2023-29406)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

The container-tools module contains tools for working with containers, notably podman, buildah, skopeo, and runc.

Security Fix(es):

• go-yaml: Improve heuristics preventing CPU/memory abuse by parsing malicious or large YAML documents (CVE-2022-3064)
• golang: html/template: improper handling of JavaScript whitespace (CVE-2023-24540)
• net/http, golang.org/x/net/http2: avoid quadratic complexity in HPACK decoding (CVE-2022-41723)
• golang: crypto/tls: large handshake records may cause panics (CVE-2022-41724)
• golang: net/http, mime/multipart: denial of service from excessive resource consumption (CVE-2022-41725)
• golang.org/x/net/html: Cross site scripting (CVE-2023-3978)
• golang: net/http, net/textproto: denial of service from excessive memory allocation (CVE-2023-24534)
• golang: net/http, net/textproto, mime/multipart: denial of service from excessive resource consumption (CVE-2023-24536)
• golang: go/parser: Infinite loop in parsing (CVE-2023-24537)
• golang: html/template: backticks not treated as string delimiters (CVE-2023-24538)
• golang: html/template: improper sanitization of CSS values (CVE-2023-24539)
• containerd: Supplementary groups are not set up properly (CVE-2023-25173)
• runc: Rootless runc makes /sys/fs/cgroup writable (CVE-2023-25809)
• runc: volume mount race condition (regression of CVE-2019-19921) (CVE-2023-27561)
• runc: AppArmor can be bypassed when /proc inside the container is symlinked with a specific mount configuration (CVE-2023-28642)
• golang: html/template: improper handling of empty HTML attributes (CVE-2023-29400)
• golang: net/http: insufficient sanitization of Host header (CVE-2023-29406)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

Rootless: /sys/fs/cgroup is writable when cgroupns isn't unshared in github.com/opencontainers/runc

/sys/fs/cgroup is writable when cgroupns isn't unshared (CVE-2023-25809) Regression that reintroduced CVE-2019-19921 - Incorrect Access Control leading to Escalation of Privileges (CVE-2023-27561) AppArmor/SELinux bypass with symlinked /proc (CVE-2023-28642)

These are all security issues fixed in the runc-1.1.5-1.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the govulncheck-vulndb-0.0.20250807T150727-1.1 package on the GA media of openSUSE Tumbleweed.

This update for runc fixes the following issues:

Update to runc v1.1.5:

Security fixes:

• CVE-2023-25809: Fixed rootless /sys/fs/cgroup is writable when cgroupns isn't unshared (bnc#1209884).
• CVE-2023-27561: Fixed regression that reintroduced CVE-2019-19921 vulnerability (bnc#1208962).
• CVE-2023-28642: Fixed AppArmor/SELinux bypass with symlinked /proc (bnc#1209888).

Other fixes:

• Fix the inability to use /dev/null when inside a container.
• Fix changing the ownership of host's /dev/null caused by fd redirection (bsc#1168481).
• Fix rare runc exec/enter unshare error on older kernels.
• nsexec: Check for errors in write_log().
• Drop version-specific Go requirement.

This update for runc fixes the following issues:

Update to runc v1.1.5:

Security fixes:

• CVE-2023-25809: Fixed rootless /sys/fs/cgroup is writable when cgroupns isn't unshared (bnc#1209884).
• CVE-2023-27561: Fixed regression that reintroduced CVE-2019-19921 vulnerability (bnc#1208962).
• CVE-2023-28642: Fixed AppArmor/SELinux bypass with symlinked /proc (bnc#1209888).

Other fixes:

• Fix the inability to use /dev/null when inside a container.
• Fix changing the ownership of host's /dev/null caused by fd redirection (bsc#1168481).
• Fix rare runc exec/enter unshare error on older kernels.
• nsexec: Check for errors in write_log().
• Drop version-specific Go requirement.

It was discovered that runC incorrectly made /sys/fs/cgroup writable when in rootless mode. An attacker could possibly use this issue to escalate privileges. (CVE-2023-25809)

It was discovered that runC incorrectly performed access control when mounting /proc to non-directories. An attacker could possibly use this issue to escalate privileges. (CVE-2023-27561)

It was discovered that runC incorrectly handled /proc and /sys mounts inside a container. An attacker could possibly use this issue to bypass AppArmor, and potentially SELinux. (CVE-2023-28642)

USN-6088-1 fixed vulnerabilities in runC. This update provides the corresponding updates for Ubuntu 16.04 LTS.

It was discovered that runC incorrectly performed access control when mounting /proc to non-directories. An attacker could possibly use this issue to escalate privileges. (CVE-2019-19921)

Felix Wilhelm discovered that runC incorrecly handled netlink messages. An attacker could possibly use this issue to escalate privileges. (CVE-2021-43784)

Andrew G. Morgan discovered that runC incorrectly set inherited process capabilities inside the container. An attacker could possibly use this issue to escalate privileges. (CVE-2022-29162)

Original advisory details:

It was discovered that runC incorrectly made /sys/fs/cgroup writable when in rootless mode. An attacker could possibly use this issue to escalate privileges. (CVE-2023-25809)

It was discovered that runC incorrectly performed access control when mounting /proc to non-directories. An attacker could possibly use this issue to escalate privileges. (CVE-2023-27561)

It was discovered that runC incorrectly handled /proc and /sys mounts inside a container. An attacker could possibly use this issue to bypass AppArmor, and potentially SELinux. (CVE-2023-28642)