hpcng / singularity

Singularity 3.6.4 is an important security release. Please read the release notes below carefully.

Security related fixes

Singularity 3.6.4 addresses the following security issues.

• CVE-2020-15229: Due to insecure handling of path traversal and the lack of path sanitization within unsquashfs (a distribution provided utility used by Singularity), it is possible to overwrite/create files on the host filesystem during the extraction of a crafted squashfs filesystem. Affects unprivileged execution of SIF / SquashFS images, and image builds from SIF / SquashFS images.

Please see the published security advisories at https://github.com/hpcng/singularity/security/advisories for full detail of these security issues.

Bug Fixes

• Update scs-library-client to support library:// backends using a 3rd party S3 object store that does not strictly conform to v4 signature spec.

Patches against prior versions

In keeping with their commitment to the open source community to release security patches incorporated into SingularityPRO, Sylabs is releasing the following diffs that contain security content only:

3.1: https://repo.sylabs.io/security/2020/CVE-2020-15229-31.diff
3.5: https://repo.sylabs.io/security/2020/CVE-2020-15229-35.diff

Thanks to our contributors for code, feedback and, testing efforts!

As always, please report any bugs to: https://github.com/hpcng/singularity/issues/new

If you think that you've discovered a security vulnerability please report it to: security@sylabs.io

Have fun!

Singularity 3.6.3 is an important security release. Please read the release notes below carefully.

Security related fixes

Singularity 3.6.3 addresses the following security issues.

• CVE-2020-25039: When a Singularity action command (run, shell, exec) is run with the fakeroot or user namespace option, Singularity will extract a container image to a temporary sandbox directory. Due to insecure permissions on the temporary directory it is possible for any user with access to the system to read the contents of the image. Additionally, if the image contains a world-writable file or directory, it is possible for a user to inject arbitrary content into the running container.

• CVE-2020-25040: When a Singularity command that results in a container build operation is executed, it is possible for a user with access to the system to read the contents of the image during the build. Additionally, if the image contains a world-writable file or directory, it is possible for a user to inject arbitrary content into the running build, which in certain circumstances may enable arbitrary code execution during the build and/or when the built container is run.

Bug Fixes

• Add CAP_MKNOD in capability bounding set of RPC to fix issue with cryptsetup when decrypting image from within a docker container.
• Fix decryption issue when using both IPC and PID namespaces.
• Fix unsupported builtins panic from shell interpreter and add umask support for definition file scripts.
• Do not load keyring in prepare_linux if ECL not enabled.
• Ensure sandbox option overrides remote build destination.

In keeping with their commitment to the open source community to release security patches incorporated into SingularityPRO, Sylabs is releasing the following diffs that contain security content only:

• 2.4: https://repo.sylabs.io/security/2020/CVE-2020-25040-24.diff
• 2.5: https://repo.sylabs.io/security/2020/CVE-2020-25040-25.diff
• 2.6: https://repo.sylabs.io/security/2020/CVE-2020-25040-26.diff
• 3.1: https://repo.sylabs.io/security/2020/CVE-2020-25040-31.diff
• 3.5: https://repo.sylabs.io/security/2020/CVE-2020-25040-35.diff

Thanks to our contributors for code, feedback and, testing efforts!

As always, please report any bugs to: https://github.com/hpcng/singularity/issues/new

If you think that you've discovered a security vulnerability please report it to: security@sylabs.io

Have fun!

Singularity 3.6.2 is a patch release fixing a number of bugs present in the previous 3.6 releases, and adding minor improvements to the delete command for library:// containers.

New features / functionalities

• Add --force option to singularity delete for non-interactive workflows.

Changed defaults / behaviours

• Default to current architecture for singularity delete.

Bug Fixes

• Respect current remote for singularity delete command.
• Allow rw as a (noop) bind option.
• Fix capability handling regression in overlay mount.
• Fix LD_LIBRARY_PATH environment override regression with --nv/--rocm.
• Fix environment variable duplication within singularity engine.
• Use -user-xattrs for unsquashfs to avoid error with rootless extraction using unsquashfs 3.4 (Ubuntu 20.04).
• Correct --no-home message for 3.6 CWD behavior.
• Don't fail if parent of cache dir not accessible.
• Fix tests for Go 1.15 Ctty handling.
• Fix additional issues with test images on ARM64.
• Fix FUSE e2e tests to use container ssh_config.

Thanks to our contributors for code, feedback and, testing efforts!

As always, please report any bugs to: https://github.com/hpcng/singularity/issues/new

If you think that you've discovered a security vulnerability please report it to: security@sylabs.io

Have fun!

Singularity 3.6.1 is a patch release fixing some bugs raised soon after the 3.6.0 release. In particular, an issue where supplying an empty string "" as the destination to singularity build could result in the removal of the current directory has been addressed. Other fixes correct problems with mksquashfs limits, environment in Singularity 2.2 containers, and address a change in overlay behavior with an improved error message.

New features / functionalities

• Support compilation with FORTIFY_SOURCE=2 and build in pie mode with fstack-protector enabled (#5433).

Bug Fixes

• Provide advisory message r.e. need for upper and work to exist in overlay images.
• Use squashfs mem and processor limits in squashfs gzip check.
• Ensure build destination path is not an empty string - do not overwrite CWD.
• Don't unset PATH when interpreting legacy /environment files.

Thanks to our contributors for code, feedback and, testing efforts!

As always, please report any bugs to: https://github.com/hpcng/singularity/issues/new

If you think that you've discovered a security vulnerability please report it to: security@sylabs.io

Have fun!

Singularity 3.6.0 is an important security release, as well as including a large number of new features and improvements. Please read the release notes below carefully, especially regarding the security content and compatibility of SIF signatures.

In particular, note that 3.6.0 necessarily uses a new format for SIF signatures, which is incompatible with older versions of Singularity. 3.6.0 has a --legacy-insecure flag to verify the older insecure signatures temporarily if needed in your workflows, but older versions cannot verify containers signed by 3.6.0.

Security related fixes

Singularity 3.6.0 introduces a new signature format for SIF images, and changes to the signing / verification code to address:

• CVE-2020-13845
  In Singularity 3.x versions below 3.6.0, issues allow the ECL to be bypassed by a malicious user.
• CVE-2020-13846
  In Singularity 3.5 the --all / -a option to singularity verify returns success even when some objects in a SIF container are not signed, or cannot be verified.
• CVE-2020-13847
  In Singularity 3.x versions below 3.6.0, Singularity's sign and verify commands do not sign metadata found in the global header or data object descriptors of a SIF file, allowing an attacker to cause unexpected behavior. A signed container may verify successfully, even when it has been modified in ways that could be exploited to cause malicious behavior.

Please see the published security advisories at https://github.com/hpcng/singularity/security/advisories for full detail of these security issues.

Note that the new signature format is necessarily incompatible with Singularity < 3.6.0 - e.g. Singularity 3.5.3 cannot verify containers
signed by 3.6.0.

We thank Tru Huynh for a report that led to the review of, and changes to, the signature implementation.

New features / functionalities

• Singularity now supports the execution of minimal Docker/OCI containers that do not contain /bin/sh, e.g. docker://hello-world.
• A new cache structure is used that is concurrency safe on a filesystem that supports atomic rename. If you downgrade to Singularity 3.5 or older after using 3.6 you will need to run singularity cache clean.
• A plugin system rework adds new hook points that will allow the development of plugins that modify behavior of the runtime. An image driver concept is introduced for plugins to support new ways of handling image and overlay mounts. Plugins built for <=3.5 are not compatible with 3.6.
• The --bind flag can now bind directories from a SIF or ext3 image into a container.
• The --fusemount feature to mount filesystems to a container via FUSE drivers is now a supported feature (previously an experimental hidden flag). This permits users to mount e.g. sshfs and cvmfs filesystems to the container at runtime.
• A new -c/--config flag allows an alternative singularity.conf to be specified by the root user, or all users in an unprivileged installation.
• A new --env flag allows container environment variables to be set via the Singularity command line.
• A new --env-file flag allows container environment variables to be set from a specified file.
• A new --days flag for cache clean allows removal of items older than a specified number of days. Replaces the --name flag which is not generally useful as the cache entries are stored by hash, not a friendly name.
• A new '--legacy-insecure' flag to verify allows verification of SIF signatures in the old, insecure format.
• A new '-l / --logs' flag for instance list that shows the paths to instance STDERR / STDOUT log files.
• The --json output of instance list now include paths to STDERR / STDOUT log files.

Changed defaults / behaviours

• New signature format (see security fixes above).
• Environment variables prefixed with SINGULARITYENV_ always take precedence over variables without SINGULARITYENV_ prefix.
• The %post build section inherits environment variables from the base image.
• %files from ... will now follow symlinks for sources that are directly specified, or directly resolved from a glob pattern. It will not follow symlinks found through directory traversal. This mirrors Docker multi-stage COPY behaviour.
• Restored the CWD mount behaviour of v2, implying that CWD path is not recreated inside container and any symlinks in the CWD path are not resolved anymore to determine the destination path inside container.
• The %test build section is executed the same manner as singularity test image.
• --fusemount with the container: default directive will foreground the FUSE process. Use container-daemon: for previous behavior.
• Fixed spacing of singularity instance list to be dynamically changing based off of input lengths instead of fixed number of spaces to account for long instance names.

Deprecated / removed commands

• Removed --name flag for cache clean; replaced with --days.
• Deprecate -a / --all option to sign/verify as new signature behavior makes this the default.

Bug Fixes

• Don't try to mount $HOME when it is / (e.g. nobody user).
• Process %appinstall sections in order when building from a definition file.
• Ensure SINGULARITY_CONTAINER, SINGULARITY_ENVIRONMENT and the custom shell prompt are set inside a container.
• Honor insecure registry settings from /etc/containers/registries.conf.
• Fix http_proxy env var handling in yum bootstrap builds.
• Disable log colorization when output location is not a terminal.
• Check encryption keys are usable before beginning an encrypted build.
• Allow app names with non-alphanumeric characters.
• Use the base metapackage for arch bootstrap builds - arch no longer has a base group.
• Ensure library client messages are logged with --debug.
• Do not mount $HOME with --fakeroot --contain.
• Fall back to underlay automatically when using a sandbox on GPFS.
• Fix Ctrl-Z handling - propagation of signal.

Thanks to our contributors for code, feedback and, testing efforts!

As always, please report any bugs to: https://github.com/sylabs/singularity/issues/new

If you think that you've discovered a security vulnerability please report it to: security@sylabs.io

Have fun!