GHSA-qvc4-78gw-pv8p
Adverserial use of `make_bitflags!` macro can cause undefined behavior
GHSA-qvc4-78gw-pv8p is a vulnerability with no CVSS score yet in enumflags2, published April 17, 2023. No source lists public exploit code. Fixed in enumflags2 0.7.7.
- Severity
- UnratedNo CVSS score yet
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
0.7.7enumflags2
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
| Package | Affected | Fixed |
|---|---|---|
enumflags2crates.io | 0.7.0 up to 0.7.7 | 0.7.7 |
What each source reports
GitHub AdvisoriesNo score
Adverserial use of `make_bitflags!` macro can cause undefined behavior
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
}
- Record
GHSA-qvc4-78gw-pv8p- Updated
- 2026-11-02
OSVNo score
Adverserial use of `make_bitflags!` macro can cause undefined behavior
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
}
- Record
GHSA-qvc4-78gw-pv8p- Updated
- 2026-11-02
OSVRUSTSEC-2023-0035No score
Adverserial use of `make_bitflags!` macro can cause undefined behavior
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
}
- Record
RUSTSEC-2023-0035- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.