CVE-2021-23336

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 ID
• CVE-2021-23336

• Assigner
• report@snyk.io

• Vulnerability Status
• Analyzed

• Published Version
• 2021-02-15T13:15:12

• Last Modified Date
• 2022-03-04T19:13:15

• Version
• 2.0

• Vector String
• AV:N/AC:H/Au:N/C:N/I:P/A:P

• Access Vector
• NETWORK

• Access Compatibility
• HIGH

• Authentication
• NONE

• Confidentiality Impact
• NONE

• Integrity Impact
• PARTIAL

• Availability Impact
• PARTIAL

• Base Score
• 4

• Severity
• MEDIUM

• Exploitability Score
• 4.9

• Impact Score
• 4.9

• Version
• 3.1

• Vector String
• CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H

• Attack Vector
• NETWORK

• Attack Compatibility
• HIGH

• Privileges Required
• NONE

• User Interaction
• REQUIRED

• Scope
• UNCHANGED

• Confidentiality Impact
• NONE

• Availability Impact
• HIGH

• Base Score
• 5.9

• Base Severity
• MEDIUM

• Exploitability Score
• 1.6

• Impact Score
• 4.2