RUSTSEC-2020-0071: Potential segfault in the time crate

[github-actions]

Potential segfault in the time crate

Details
Package	time
Version	0.1.43
URL	time-rs/time#293
Date	2020-11-18
Patched versions	>=0.2.23
Unaffected versions	=0.2.0,=0.2.1,=0.2.2,=0.2.3,=0.2.4,=0.2.5,=0.2.6

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

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

No workarounds are known.

References

time-rs/time#293

See advisory page for additional details.

[thanethomson]

Seems like this is largely chrono-related.

[tony-iqlusion]

Yes. In fact chrono has a similar problem (RUSTSEC-2020-0159) which still isn't fixed.

I'm not even sure why you need chrono? I guess it was added in #994 a few weeks ago but it is far more complicated than you need. You only really need chrono if you're dealing with time zones. Otherwise something like time::PrimitiveDateTime is sufficient.

There are also many complaints, especially surrounding both of these recent vulnerabilities, that chrono is poorly maintained with issues addressing critical bugs open for prolonged periods of time.

[thanethomson]

Good points @tony-iqlusion. Let's investigate what it'd take to remove chrono - I'll open a follow-up issue!

[soareschen]

Looks like a new version of time has just been released.