OESA-2021-1125 (CVE-2021-23336)
Vulnerability from osv_openeuler – Published: 2021-04-07 11:04 – Updated: 2026-08-06 11:04 – Source websitePython combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.
Security Fix(es):
The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.(CVE-2021-23336)
| URL | Type | |
|---|---|---|
{
"affected": [
{
"ecosystem_specific": {
"aarch64": [
"python3-debug-3.7.9-8.oe1.aarch64.rpm",
"python3-devel-3.7.9-8.oe1.aarch64.rpm",
"python3-debugsource-3.7.9-8.oe1.aarch64.rpm",
"python3-3.7.9-8.oe1.aarch64.rpm",
"python3-debuginfo-3.7.9-8.oe1.aarch64.rpm",
"python3-3.7.9-10.oe1.aarch64.rpm",
"python3-debug-3.7.9-10.oe1.aarch64.rpm",
"python3-debuginfo-3.7.9-10.oe1.aarch64.rpm",
"python3-devel-3.7.9-10.oe1.aarch64.rpm",
"python3-debugsource-3.7.9-10.oe1.aarch64.rpm"
],
"noarch": [
"python3-help-3.7.9-8.oe1.noarch.rpm",
"python3-help-3.7.9-10.oe1.noarch.rpm"
],
"src": [
"python3-3.7.9-8.oe1.src.rpm",
"python3-3.7.9-10.oe1.src.rpm"
],
"x86_64": [
"python3-3.7.9-8.oe1.x86_64.rpm",
"python3-debugsource-3.7.9-8.oe1.x86_64.rpm",
"python3-debug-3.7.9-8.oe1.x86_64.rpm",
"python3-debuginfo-3.7.9-8.oe1.x86_64.rpm",
"python3-devel-3.7.9-8.oe1.x86_64.rpm",
"python3-debugsource-3.7.9-10.oe1.x86_64.rpm",
"python3-3.7.9-10.oe1.x86_64.rpm",
"python3-debuginfo-3.7.9-10.oe1.x86_64.rpm",
"python3-debug-3.7.9-10.oe1.x86_64.rpm",
"python3-devel-3.7.9-10.oe1.x86_64.rpm"
]
},
"package": {
"ecosystem": "openEuler:20.03-LTS",
"name": "python3",
"purl": "pkg:rpm/openEuler/python3\u0026distro=openEuler-20.03-LTS"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.7.9-10.oe1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"ecosystem_specific": {
"aarch64": [
"python3-3.7.9-10.oe1.aarch64.rpm",
"python3-debug-3.7.9-10.oe1.aarch64.rpm",
"python3-debuginfo-3.7.9-10.oe1.aarch64.rpm",
"python3-devel-3.7.9-10.oe1.aarch64.rpm",
"python3-debugsource-3.7.9-10.oe1.aarch64.rpm"
],
"noarch": [
"python3-help-3.7.9-10.oe1.noarch.rpm"
],
"src": [
"python3-3.7.9-10.oe1.src.rpm"
],
"x86_64": [
"python3-debugsource-3.7.9-10.oe1.x86_64.rpm",
"python3-3.7.9-10.oe1.x86_64.rpm",
"python3-debuginfo-3.7.9-10.oe1.x86_64.rpm",
"python3-debug-3.7.9-10.oe1.x86_64.rpm",
"python3-devel-3.7.9-10.oe1.x86_64.rpm"
]
},
"package": {
"ecosystem": "openEuler:20.03-LTS-SP1",
"name": "python3",
"purl": "pkg:rpm/openEuler/python3\u0026distro=openEuler-20.03-LTS-SP1"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.7.9-10.oe1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"severity": "High"
},
"details": "Python combines remarkable power with very clear syntax. It has modules, classes, exceptions, very high level dynamic data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems. New built-in modules are easily written in C or C++ (or other languages, depending on the chosen implementation). Python is also usable as an extension language for applications written in other languages that need easy-to-use scripting or automation interfaces.\r\n\r\nSecurity Fix(es):\r\n\r\nThe package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking. When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.(CVE-2021-23336)",
"id": "OESA-2021-1125",
"modified": "2026-08-06T11:04:21Z",
"published": "2021-04-07T11:04:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2021-1125"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-23336"
}
],
"schema_version": "1.7.2",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H",
"type": "CVSS_V3"
}
],
"summary": "python3 security update",
"upstream": [
"CVE-2021-23336"
]
}
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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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