{"id":"GHSA-wrw7-89jp-8q8g","summary":"Unsoundness in `Iterator` and `DoubleEndedIterator` impls for `glib::VariantStrIter`","details":"The `VariantStrIter::impl_get` function (called internally by implementations of the `Iterator` and `DoubleEndedIterator` traits for this type) was unsound, resulting in undefined behaviour.\n\nAn immutable reference `&p` to a `*mut libc::c_char` pointer initialized to `NULL` was passed as an argument to a C function that that mutates the pointer behind `&p` in-place (i.e. as an out-argument), which was unsound. After changes in recent versions of the Rust compiler, these unsound writes through `&p` now seem to be completely disregarded when building the `glib` crate with optimizations.\n\nThis subsequently caused all calls of `VariantStrIter::impl_get` to violate the safety requirements of the `std::ffi::CStr::from_ptr` function - which requires its argument to be a valid pointer to a C-style string - resulting in crashes due to `NULL` pointer dereferences.\n\nThis was fixed by passing the out-argument pointer explitly as `&mut p` instead of `&p`.\n\nThis issue has been present since this code was initially added in `glib` v0.15.0. The mismatch in mutability was likely missed (and not raised as an error by the compiler) because the C function wrapped by `VariantStrIter::impl_get` is variadic (`glib_sys::g_variant_get_child`), and the pointer in question is one of the variadic arguments.\n\n","aliases":["RUSTSEC-2024-0429"],"modified":"2025-10-28T06:29:26.473225Z","published":"2024-12-23T20:19:24Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2024-12-23T20:19:24Z","nvd_published_at":null,"cwe_ids":[],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/gtk-rs/gtk-rs-core/pull/1343"},{"type":"PACKAGE","url":"https://github.com/gtk-rs/gtk-rs-core"},{"type":"WEB","url":"https://rustsec.org/advisories/RUSTSEC-2024-0429.html"}],"affected":[{"package":{"name":"glib","ecosystem":"crates.io","purl":"pkg:cargo/glib"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.15.0"},{"fixed":"0.20.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/12/GHSA-wrw7-89jp-8q8g/GHSA-wrw7-89jp-8q8g.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"}]}