GHSA-5JFW-GQ64-Q45F
Vulnerability from github – Published: 2024-11-19 21:07 – Updated: 2025-01-14 16:37Impact
The HTML Parser in lxml does not properly handle context-switching for special HTML tags such as <svg>, <math> and <noscript>. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content.
Patches
Users employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue.
Workarounds
As a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability:
* remove_tags: Specify tags to remove - their content is moved to their parents' tags.
* kill_tags: Specify tags to be removed completely.
* allow_tags: Restrict the set of permissible tags, excluding context-switching tags like <svg>, <math> and <noscript>.
References
- https://github.com/fedora-python/lxml_html_clean/pull/19
- https://github.com/fedora-python/lxml_html_clean/pull/19/commits/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "lxml-html-clean"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.4.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-52595"
],
"database_specific": {
"cwe_ids": [
"CWE-184",
"CWE-79",
"CWE-83"
],
"github_reviewed": true,
"github_reviewed_at": "2024-11-19T21:07:59Z",
"nvd_published_at": "2024-11-19T22:15:21Z",
"severity": "HIGH"
},
"details": "### Impact\n\nThe HTML Parser in lxml does not properly handle context-switching for special HTML tags such as `\u003csvg\u003e`, `\u003cmath\u003e` and `\u003cnoscript\u003e`. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content.\n\n### Patches\n\nUsers employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue.\n\n### Workarounds\n\nAs a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability:\n* `remove_tags`: Specify tags to remove - their content is moved to their parents\u0027 tags.\n* `kill_tags`: Specify tags to be removed completely.\n* `allow_tags`: Restrict the set of permissible tags, excluding context-switching tags like `\u003csvg\u003e`, `\u003cmath\u003e` and `\u003cnoscript\u003e`.\n\n### References\n\n* https://github.com/fedora-python/lxml_html_clean/pull/19\n* https://github.com/fedora-python/lxml_html_clean/pull/19/commits/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808\n",
"id": "GHSA-5jfw-gq64-q45f",
"modified": "2025-01-14T16:37:30Z",
"published": "2024-11-19T21:07:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-5jfw-gq64-q45f"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-52595"
},
{
"type": "WEB",
"url": "https://github.com/fedora-python/lxml_html_clean/pull/19"
},
{
"type": "WEB",
"url": "https://github.com/fedora-python/lxml_html_clean/commit/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808"
},
{
"type": "PACKAGE",
"url": "https://github.com/fedora-python/lxml_html_clean"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/lxml-html-clean/PYSEC-2024-160.yaml"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H",
"type": "CVSS_V3"
}
],
"summary": "HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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