ghsa-h97m-ww89-6jmq
Vulnerability from github
idna 0.5.0 and earlier accepts Punycode labels that do not produce any non-ASCII output, which means that either ASCII labels or the empty root label can be masked such that they appear unequal without IDNA processing or when processed with a different implementation and equal when processed with idna 0.5.0 or earlier.
Concretely, example.org and xn--example-.org become equal after processing by idna 0.5.0 or earlier. Also, example.org.xn-- and example.org. become equal after processing by idna 0.5.0 or earlier.
In applications using idna (but not in idna itself) this may be able to lead to privilege escalation when host name comparison is part of a privilege check and the behavior is combined with a client that resolves domains with such labels instead of treating them as errors that preclude DNS resolution / URL fetching and with the attacker managing to introduce a DNS entry (and TLS certificate) for an xn---masked name that turns into the name of the target when processed by idna 0.5.0 or earlier.
Remedy
Upgrade to idna 1.0.3 or later, if depending on idna directly, or to url 2.5.4 or later, if depending on idna via url. (This issue was fixed in idna 1.0.0, but versions earlier than 1.0.3 are not recommended for other reasons.)
When upgrading, please take a moment to read about alternative Unicode back ends for idna.
If you are using Rust earlier than 1.81 in combination with SQLx 0.8.2 or earlier, please also read an issue about combining them with url 2.5.4 and idna 1.0.3.
Additional information
This issue resulted from idna 0.5.0 and earlier implementing the UTS 46 specification literally on this point and the specification having this bug. The specification bug has been fixed in revision 33 of UTS 46.
Acknowledgements
Thanks to kageshiron for recognizing the security implications of this behavior.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "idna"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-12224"
],
"database_specific": {
"cwe_ids": [
"CWE-1289",
"CWE-697"
],
"github_reviewed": true,
"github_reviewed_at": "2024-12-09T20:41:10Z",
"nvd_published_at": "2025-05-30T02:15:19Z",
"severity": "MODERATE"
},
"details": "`idna` 0.5.0 and earlier accepts Punycode labels that do not produce any non-ASCII output, which means that either ASCII labels or the empty root label can be masked such that they appear unequal without IDNA processing or when processed with a different implementation and equal when processed with `idna` 0.5.0 or earlier.\n\nConcretely, `example.org` and `xn--example-.org` become equal after processing by `idna` 0.5.0 or earlier. Also, `example.org.xn--` and `example.org.` become equal after processing by `idna` 0.5.0 or earlier.\n\nIn applications using `idna` (but not in `idna` itself) this may be able to lead to privilege escalation when host name comparison is part of a privilege check and the behavior is combined with a client that resolves domains with such labels instead of treating them as errors that preclude DNS resolution / URL fetching and with the attacker managing to introduce a DNS entry (and TLS certificate) for an `xn--`-masked name that turns into the name of the target when processed by `idna` 0.5.0 or earlier.\n\n## Remedy\n\nUpgrade to `idna` 1.0.3 or later, if depending on `idna` directly, or to `url` 2.5.4 or later, if depending on `idna` via `url`. (This issue was fixed in `idna` 1.0.0, but versions earlier than 1.0.3 are not recommended for other reasons.)\n\nWhen upgrading, please take a moment to read about [alternative Unicode back ends for `idna`](https://docs.rs/crate/idna_adapter/latest).\n\nIf you are using Rust earlier than 1.81 in combination with SQLx 0.8.2 or earlier, please also read an [issue](https://github.com/servo/rust-url/issues/992) about combining them with `url` 2.5.4 and `idna` 1.0.3.\n\n## Additional information\n\nThis issue resulted from `idna` 0.5.0 and earlier implementing the UTS 46 specification literally on this point and the specification having this bug. The specification bug has been fixed in [revision 33 of UTS 46](https://www.unicode.org/reports/tr46/tr46-33.html#Modifications).\n\n## Acknowledgements\n\nThanks to kageshiron for recognizing the security implications of this behavior.",
"id": "GHSA-h97m-ww89-6jmq",
"modified": "2025-05-30T15:01:30Z",
"published": "2024-12-09T20:41:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-12224"
},
{
"type": "WEB",
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1887898"
},
{
"type": "PACKAGE",
"url": "https://github.com/servo/rust-url"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2024-0421.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "`idna` accepts Punycode labels that do not produce any non-ASCII when decoded"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.