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Segmentation fault in time

Moderate severity GitHub Reviewed Published Nov 18, 2020 in time-rs/time • Updated Jun 10, 2024

Package

cargo time (Rust)

Affected versions

>= 0.2.7, < 0.2.23
>= 0.1.0, < 0.2.0

Patched versions

0.2.23
0.2.23

Description

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

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.

References

time-rs/time#293.

References

@jhpratt jhpratt published to time-rs/time Nov 18, 2020
Published by the National Vulnerability Database Nov 24, 2020
Reviewed Aug 18, 2021
Published to the GitHub Advisory Database Aug 25, 2021
Last updated Jun 10, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.107%
(45th percentile)

Weaknesses

CVE ID

CVE-2020-26235

GHSA ID

GHSA-wcg3-cvx6-7396

Source code

Credits

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