Vulnerabilities

RUSTSEC-2021-0119

Out-of-bounds write in nix::unistd::getgrouplist

On certain platforms, if a user has more than 16 groups, the
nix::unistd::getgrouplist function will call the libc getgrouplist
function with a length parameter greater than the size of the buffer it
provides, resulting in an out-of-bounds write and memory corruption.

The libc getgrouplist function takes an in/out parameter ngroups
specifying the size of the group buffer. When the buffer is too small to
hold all of the requested user's group memberships, some libc
implementations, including glibc and Solaris libc, will modify ngroups
to indicate the actual number of groups for the user, in addition to
returning an error. The version of nix::unistd::getgrouplist in nix
0.16.0 and up will resize the buffer to twice its size, but will not
read or modify the ngroups variable. Thus, if the user has more than
twice as many groups as the initial buffer size of 8, the next call to
getgrouplist will then write past the end of the buffer.

The issue would require editing /etc/groups to exploit, which is usually
only editable by the root user.

RUSTSEC-2022-0040

Multiple soundness issues in owning_ref

• OwningRef::map_with_owner is unsound and may result in a use-after-free.
• OwningRef::map is unsound and may result in a use-after-free.
• OwningRefMut::as_owner and OwningRefMut::as_owner_mut are unsound and may result in a use-after-free.
• The crate violates Rust's aliasing rules, which may cause miscompilations on recent compilers that emit the LLVM noalias attribute.

No patched versions are available at this time. While a pull request with some fixes is outstanding, the maintainer appears to be unresponsive.

RUSTSEC-2020-0071

Potential segfault in the time crate

Impact

Unix-like operating systems may segfault due to dereferencing a dangling pointer in specific circumstances. This requires an environment variable to be set in a different thread than the affected functions. This may occur without the user's knowledge, notably in a third-party library.

The affected functions from time 0.2.7 through 0.2.22 are:

• time::UtcOffset::local_offset_at
• time::UtcOffset::try_local_offset_at
• time::UtcOffset::current_local_offset
• time::UtcOffset::try_current_local_offset
• time::OffsetDateTime::now_local
• time::OffsetDateTime::try_now_local

The affected functions in time 0.1 (all versions) are:

• at
• at_utc
• now

Non-Unix targets (including Windows and wasm) are unaffected.

Patches

Pending a proper fix, the internal method that determines the local offset has been modified to always return None on the affected operating systems. This has the effect of returning an Err on the try_* methods and UTC on the non-try_* methods.

Users and library authors with time in their dependency tree should perform cargo update, which will pull in the updated, unaffected code.

Users of time 0.1 do not have a patch and should upgrade to an unaffected version: time 0.2.23 or greater or the 0.3 series.

Workarounds

A possible workaround for crates affected through the transitive dependency in chrono, is to avoid using the default oldtime feature dependency of the chrono crate by disabling its default-features and manually specifying the required features instead.

Examples:

Cargo.toml:

chrono = { version = "0.4", default-features = false, features = ["serde"] }

chrono = { version = "0.4.22", default-features = false, features = ["clock"] }

Commandline:

cargo add chrono --no-default-features -F clock

Sources:

• chronotope/chrono#602 (comment)
• vityafx/serde-aux#21

Warnings

RUSTSEC-2021-0139

ansi_term is Unmaintained

The maintainer has advised that this crate is deprecated and will not receive any maintenance.

The crate does not seem to have much dependencies and may or may not be ok to use as-is.

Last release seems to have been three years ago.

Possible Alternative(s)

The below list has not been vetted in any way and may or may not contain alternatives;

• anstyle
• console
• nu-ansi-term
• owo-colors
• stylish
• yansi

Dependency Specific Migration(s)

• structopt, clap2