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
In some versions of time, 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. In later versions, time will attempt to determine the number of threads running in the process. If the process is single-threaded, the call will proceed as its safety invariant is upheld.
Users and library authors with time in their dependency tree must perform cargo update, which will pull in the updated, unaffected code.
Users of time 0.1 do not have a patch and must upgrade to an unaffected version: time 0.2.23 or greater or the 0.3 series.
Workarounds
Library authors must ensure that the program only has one running thread at the time of calling any affected method. Binary authors may do the same and/or ensure that no other thread is actively mutating the environment.
djc
commented
1 year ago
Chrono v4.x seems to be using a 0.1.x version of the time crate which seems to have a vulnerability.
Until v5.x is ready it should be made sure that v4.x is not vulnerable
For reference, in my repo I got a dependabot allert that reads the following:
Segmentation fault in time
Package: time (Rust) Affected versions: >= 0.1.0, < 0.2.0 Patched version: 0.2.23
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_attime::UtcOffset::try_local_offset_attime::UtcOffset::current_local_offsettime::UtcOffset::try_current_local_offsettime::OffsetDateTime::now_localtime::OffsetDateTime::try_now_localThe affected functions in time 0.1 (all versions) are:
atat_utcnowNon-Unix targets (including Windows and wasm) are unaffected.
Patches
In some versions of
time, the internal method that determines the local offset has been modified to always returnNoneon the affected operating systems. This has the effect of returning anErron thetry_*methods andUTCon the non-try_*methods. In later versions,timewill attempt to determine the number of threads running in the process. If the process is single-threaded, the call will proceed as its safety invariant is upheld.Users and library authors with time in their dependency tree must perform
cargo update, which will pull in the updated, unaffected code.Users of time 0.1 do not have a patch and must upgrade to an unaffected version: time 0.2.23 or greater or the 0.3 series.
Workarounds
Library authors must ensure that the program only has one running thread at the time of calling any affected method. Binary authors may do the same and/or ensure that no other thread is actively mutating the environment.
References
time-rs/time#293.