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GHSA-qvc4-78gw-pv8p — enumflags2

GHSA-qvc4-78gw-pv8p is a security vulnerability in enumflags2. A fix is available for enumflags2 — see the affected versions and patch details below.

Adverserial use of `make_bitflags!` macro can cause undefined behavior

Also known asRUSTSEC-2023-0035
Published
Apr 24, 2023
Updated
Nov 8, 2023
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 8, 2023 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected
🦀enumflags2

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

The macro relied on an expression of the form Enum::Variant always being a variant of the enum. However, it may also be an associated integer constant, in which case there's no guarantee that the value of said constant consists only of bits valid for this bitflag type.

Thus, code like this could create an invalid BitFlags<Test>, which would cause iterating over it to trigger undefined behavior. As the debug formatter internally iterates over the value, it is also affected.

use enumflags2::{bitflags, make_bitflags};

#[bitflags]
#[repr(u8)]
#[derive(Copy, Clone, Debug)]
enum Test {
    A = 1,
    B = 2,
}

impl Test {
    const C: u8 = 69;
}

fn main() {
    let x = make_bitflags!(Test::{C});
    // printing or iterating over x is UB
}

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.ioenumflags2≥ 0.7.0&&< 0.7.70.7.7cargo update -p enumflags2 --precise 0.7.7

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for enumflags2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update enumflags2 to 0.7.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qvc4-78gw-pv8p is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-qvc4-78gw-pv8p can be triaged on real exposure rather than presence alone.

Tailored to GHSA-qvc4-78gw-pv8p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

The macro relied on an expression of the form `Enum::Variant` always being a variant of the enum. However, it may also be an associated integer constant, in which case there's no guarantee that the value of said constant consists only of bits valid for this bitflag type. Thus, code like this could create an invalid `BitFlags<Test>`, which would cause iterating over it to trigger undefined behavior. As the debug formatter internally iterates over the value, it is also affected. ```rust use enumflags2::{bitflags, make_bitflags}; #[bitflags] #[repr(u8)] #[derive(Copy, Clone, Debug)] enum Test
O3 Security · Impact-Aware SCA

Is GHSA-qvc4-78gw-pv8p in your dependencies?

O3 Security finds GHSA-qvc4-78gw-pv8p across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

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GHSA-qvc4-78gw-pv8p: enumflags2 | O3 Security