# GHSA-45w3-v3g4-54pm: Chrono has potential segfault issue in SPIFFE authenticator

> A race condition in the chrono library can cause a segfault in the Parsec SPIFFE authenticator, leading to thread termination and potential service disruption.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Feb 2022

## What is GHSA-45w3-v3g4-54pm?

GHSA-45w3-v3g4-54pm is a denial of service vulnerability in parsec-service, published on 11 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

### Impact
Several vulnerabilities have been reported in the `time` and `chrono` crates related to handling of calls to `localtime_r`. You can follow some of the discussions [here](https://github.com/chronotope/chrono/issues/602) and [here](https://github.com/time-rs/time/issues/293), and the associated CVE [here](https://nvd.nist.gov/vuln/detail/CVE-2020-26235). In our case, the issue with the dependency was flagged by our nightly CI build running [`cargo-audit`](https://github.com/parallaxsecond/parsec/issues/544). 

The vulnerability leads to a segfault in specific circumstances - namely, when one of a number of functions in the `time` crate is called while any other thread is setting an environment variable. Given that in the case of the Parsec service this affects the SPIFFE authenticator, Parsec service users can encounter the issue only when the JWT SVID authenticator is enabled and being used. We have not undergone any manual tracing to understand if the vulnerable methods are called anywhere in our stack, however it seems reasonable to expect that if that were to be the case, the issue would lie in JWT validation (i.e. when handling the dates found within a Json Web Token). JWT validation could thus fail, bringing down the thread in which the request happens. The rest of the threads continue to work. Since the threadpool implementation that we use [continues replenishing the pool](https://docs.rs/threadpool/latest/threadpool/) when one thread panics, the impact on the service should be minimal.

### Patches
No current patches exist as the problems lie in a number of dependencies that are not under our control (see more details [here](https://github.com/parallaxsecond/parsec/issues/544#issuecomment-1024185688)).

The issue tracking the required change in the `rust-spiffe` crate (through which the vulnerable dependencies are imported in Parsec) can be seen [here](https://github.com/maxlambrecht/rust-spiffe/issues/17). Once updates happen in our dependency chain that allow us to update beyond the vulnerable versions of `time` and `chrono`, a new version of the Parsec service will be tagged and released with the appropriate notifications.

### Workarounds
The only complete workaround is to use a different type of authenticator with the Parsec service. 

### References
As quoted in the initial paragraph, you can find out more information:
* in the `chrono` repo issue [here](https://github.com/chronotope/chrono/issues/602)
* in the `time` repo issue [here](https://github.com/time-rs/time/issues/293)
* in the official CVE report [here](https://nvd.nist.gov/vuln/detail/CVE-2020-26235)
* in our tracking issue [here](https://github.com/parallaxsecond/parsec/issues/544)

### For more information:
If you have any questions or comments about this advisory:
* Open an issue in [the Parsec service repo](https://github.com/parallaxsecond/parsec)
* Email us at [cncf-parsec-maintainers@lists.cncf.io](mailto:cncf-parsec-maintainers@lists.cncf.io)

## Which versions are affected by GHSA-45w3-v3g4-54pm?

2 open source packages ship an affected version, including parsec-service.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `parsec-service` | crates.io | From 0.8.0 | 1.1.0 |
| `parsec-service` | crates.io | From 0.8.0 | 1.1.0 |

## How do I fix GHSA-45w3-v3g4-54pm?

Upgrade parsec-service to 1.1.0 or later.

## Is GHSA-45w3-v3g4-54pm being exploited?

There is no known exploitation of GHSA-45w3-v3g4-54pm in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-45w3-v3g4-54pm and fix it if it is affected.

What it is: GHSA-45w3-v3g4-54pm is a denial of service vulnerability in parsec-service, published on 11 Feb 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-45w3-v3g4-54pm in the wild and no public exploit code.

Affected packages and fixed versions:
- parsec-service (crates.io): affected from 0.8.0; fixed in 1.1.0
- parsec-service (crates.io): affected from 0.8.0; fixed in 1.1.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-45w3-v3g4-54pm/ (Markdown: https://insights.sbomify.com/GHSA-45w3-v3g4-54pm/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-45w3-v3g4-54pm

---
From sbomify Insights: https://insights.sbomify.com/GHSA-45w3-v3g4-54pm/
Summaries are generated and may contain mistakes; the official description above is the record.