
=====================================================================

                              CERT-Renater

                    Note d'Information No. 2023/VULN265

_____________________________________________________________________

DATE                : 25/08/2023

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running cargo versions prior to 1.72.

=====================================================================
https://github.com/rust-lang/cargo/security/advisories/GHSA-wrrj-h57r-vx9p
_____________________________________________________________________


Malicious dependencies can inject arbitrary JavaScript into
cargo-generated timing reports
Low
Manishearth published GHSA-wrrj-h57r-vx9p Aug 24, 2023

Package
cargo (Rust)

Affected versions
>= 1.60.0, < 1.72

Patched versions
1.72


Description

The Rust Security Response WG was notified that Cargo did not
escape Cargo feature names when including them in the report
generated by cargo build --timings. A malicious package
included as a dependency may inject nearly arbitrary HTML
here, potentially leading to XSS if the report is subsequently
uploaded somewhere.

The severity of this vulnerability is "low" for users relying
on dependencies from git, local paths, or alternative registries.
Users who solely depend on crates.io are unaffected.

Note that by design Cargo allows code execution at build time,
due to build scripts and procedural macros. The vulnerability
in this advisory allows performing a subset of the possible
damage in a harder to track down way. Your dependencies must
still be trusted if you want to be protected from attacks,
as it's possible to perform the same attacks with build
scripts and procedural macros.


Overview

Rust 1.60.0 introduced cargo build --timings, which produces
a report of how long the different steps of the build process
took. It includes lists of Cargo features for each crate.

Prior to Rust 1.72, Cargo feature names were allowed to contain
almost any characters (with some exceptions as used by the
feature syntax), but it would produce a future incompatibility
warning about them since Rust 1.49. crates.io is far more
stringent about what it considers a valid feature name and has
not allowed such feature names.

As the feature names were included unescaped in the timings
report, they could be used to inject Javascript into the page,
for example with a feature name like features = ["<img 
src=''onerror=alert(0)"].
If this report were subsequently uploaded to a domain that
uses credentials, the injected Javascript could access
resources from the website visitor.

This issue was fixed by turning the future incompatibility
warning into an error.


Affected versions

The vulnerability is present in all versions of Cargo after
and including 1.60.0. Rust 1.72, to be released on August 24,
will include a fix for it.

Users whose dependencies are entirely on crates.io are
unaffected.


Mitigations

We recommend users always excercise care in which package they
download, by only including trusted dependencies in their
projects. Please note that even with these vulnerabilities fixed,
by design Cargo allows arbitrary code execution at build time
thanks to build scripts and procedural macros: a malicious
dependency will be able to cause damage regardless of these
vulnerabilities.

crates.io has server-side checks preventing this attack, and
there are no packages on crates.io exploiting these
vulnerabilities. crates.io users still need to excercise
care in choosing their dependencies though, as remote code
execution is allowed by design there as well.


Acknowledgements

We want to thank Remo Pas for responsibly disclosing this
to us according to the Rust security policy.

We also want to thank the members of the Rust project who
helped us disclose the vulnerability: Eric Huss for developing
the fixe, Weihang Lo and Ed Page for reviewing the fix, and
Manish Goregaokar for writing this advisory. The disclosure
was coordinated by Manish Goregaokar, Pietro Albini, and
Josh Stone.


Severity
Low

CVE ID
CVE-2023-40030

Weaknesses
No CWEs


Credits

     @cuviper cuviper Coordinator
     @remkop22 remkop22 Reporter
     @ehuss ehuss Remediation developer
     @weihanglo weihanglo Remediation reviewer
     @Manishearth Manishearth Coordinator


=========================================================
+ CERT-RENATER        |    tel : 01-53-94-20-44         +
+ 23/25 Rue Daviel    |    fax : 01-53-94-20-41         +
+ 75013 Paris         |   email:cert@support.renater.fr +
=========================================================

