This update for singularity fixes the following issues:
- New version 3.6.0. This version introduces a new signature format for
SIF images, and changes to the signing / verification code to address
the following security problems:
- CVE-2020-13845, boo#1174150 In Singularity 3.x versions below 3.6.0,
issues allow the ECL to be bypassed by a malicious user.
- CVE-2020-13846, boo#1174148 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, boo#1174152 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.
- New features / functionalities
- 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.
- 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
- The --fusemount feature to mount filesystems to a container via FUSE
drivers is now a supported feature (previously an experimental hidden
- 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
- 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
- Changed defaults / behaviours - New signature format (see security fixes above).
- 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.
- Environment variables prefixed with SINGULARITYENV_ always take
precedence over variables without SINGULARITYENV_ prefix.
- The %post build section inherits environment variables from the base
- %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
--fusemount with the container: default directive will foreground the
FUSE process. Use container-daemon: for previous behavior.
- Deprecate -a / --all option to sign/verify as new signature behavior
makes this the default.
- For more information about upstream changes, please check:
- Removed --name flag for cache clean; replaced with --days.