GHSA-P5W8-WQHJ-9HHF
Vulnerability from github – Published: 2021-09-10 17:56 – Updated: 2025-11-04 16:35Impact
The formatter function that strips comments from a SQL contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service). The regular expression may cause exponential backtracking on strings containing many repetitions of '\r\n' in SQL comments.
Patches
The issues has been fixed in sqlparse 0.4.2.
Workarounds
Only the formatting feature that removes comments from SQL statements is affected by this regular expression. As a workaround don't use the sqlformat.format function with keyword strip_comments=True or the --strip-comments command line flag when using the sqlformat command line tool.
References
This issue was discovered by GitHub team members @erik-krogh and @yoff. It was found using a CodeQL query which identifies inefficient regular expressions. You can see the results of the query on python-sqlparse by following this link.
For more information
If you have any questions or comments about this advisory: * Open an issue in sqlparse issue tracker * Email us at albrecht.andi@gmail.com
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "sqlparse"
},
"ranges": [
{
"events": [
{
"introduced": "0.4.0"
},
{
"fixed": "0.4.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-32839"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2021-09-10T17:13:29Z",
"nvd_published_at": "2021-09-20T17:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\nThe formatter function that strips comments from a SQL contains a regular expression that is vulnerable to [ReDoS](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS) (Regular Expression Denial of Service). The regular expression may cause exponential backtracking on strings containing many repetitions of \u0027\\r\\n\u0027 in SQL comments.\n\n### Patches\nThe issues has been fixed in sqlparse 0.4.2.\n\n### Workarounds\nOnly the formatting feature that removes comments from SQL statements is affected by this regular expression. As a workaround don\u0027t use the `sqlformat.format` function with keyword `strip_comments=True` or the `--strip-comments` command line flag when using the `sqlformat` command line tool.\n\n### References\nThis issue was discovered by GitHub team members @erik-krogh and @yoff. It was found using a [CodeQL](https://codeql.github.com/) query which identifies inefficient regular expressions. You can see the results of the query on python-sqlparse by following [this link](https://lgtm.com/query/2223658096471222354/). \n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [sqlparse issue tracker](https://github.com/andialbrecht/sqlparse/issues)\n* Email us at [albrecht.andi@gmail.com](mailto:albrecht.andi@gmail.com)",
"id": "GHSA-p5w8-wqhj-9hhf",
"modified": "2025-11-04T16:35:21Z",
"published": "2021-09-10T17:56:06Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-p5w8-wqhj-9hhf"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32839"
},
{
"type": "WEB",
"url": "https://github.com/andialbrecht/sqlparse/commit/8238a9e450ed1524e40cb3a8b0b3c00606903aeb"
},
{
"type": "PACKAGE",
"url": "https://github.com/andialbrecht/sqlparse"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/sqlparse/PYSEC-2021-333.yaml"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/12/msg00022.html"
},
{
"type": "ADVISORY",
"url": "https://securitylab.github.com/advisories/GHSL-2021-107-andialbrecht-sqlparse"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "StripComments filter contains a regular expression that is vulnerable to ReDOS (Regular Expression Denial of Service)"
}
Sightings
| Author | Source | Type | Date |
|---|
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.