CVE-2021-28861

Published Aug 23, 2022

Last updated 4 months ago

CVSS high 7.4

Overview

Description
Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure. NOTE: this is disputed by a third party because the http.server.html documentation page states "Warning: http.server is not recommended for production. It only implements basic security checks."
Source
cve@mitre.org
NVD status
Modified
CNA Tags
disputed
Products
python, fedora

Risk scores

CVSS 3.1

Type
Primary
Base score
7.4
Impact score
4
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-601
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-601

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. A flaw was found in libinput. An attacker capable of deploying a Lua plugin file in specific system directories can exploit a dangling pointer vulnerability. This occurs when a garbage collection cleanup function is called, leaving a pointer that can then be printed to system logs. This could potentially expose sensitive data if the memory location is re-used, leading to information disclosure. For this exploit to work, Lua plugins must be enabled in libinput and loaded by the compositor.•CVE-2026-35094
  2. A flaw was found in libinput. A local attacker who can place a specially crafted Lua bytecode file in certain system or user configuration directories can bypass security restrictions. This allows the attacker to run unauthorized code with the same permissions as the program using libinput, such as a graphical compositor. This could lead to the attacker monitoring keyboard input and sending that information to an external location.•CVE-2026-35093
  3. The webbrowser.open() API would accept leading dashes in the URL which could be handled as command line options for certain web browsers. New behavior rejects leading dashes. Users are recommended to sanitize URLs prior to passing to webbrowser.open().•CVE-2026-4519
  4. When passing data to the b64decode(), standard_b64decode(), and urlsafe_b64decode() functions in the "base64" module the characters "+/" will always be accepted, regardless of the value of "altchars" parameter, typically used to establish an "alternative base64 alphabet" such as the URL safe alphabet. This behavior matches what is recommended in earlier base64 RFCs, but newer RFCs now recommend either dropping characters outside the specified base64 alphabet or raising an error. The old behavior has the possibility of causing data integrity issues. This behavior can only be insecure if your application uses an alternate base64 alphabet (without "+/"). If your application does not use the "altchars" parameter or the urlsafe_b64decode() function, then your application does not use an alternative base64 alphabet. The attached patches DOES NOT make the base64-decode behavior raise an error, as this would be a change in behavior and break existing programs. Instead, the patch deprecates the behavior which will be replaced with the newly recommended behavior in a future version of Python. Users are recommended to mitigate by verifying user-controlled inputs match the base64 alphabet they are expecting or verify that their application would not be affected if the b64decode() functions accepted "+" or "/" outside of altchars.•CVE-2025-12781
  5. When building nested elements using xml.dom.minidom methods such as appendChild() that have a dependency on _clear_id_cache() the algorithm is quadratic. Availability can be impacted when building excessively nested documents.•CVE-2025-12084

References

Sources include official advisories and independent security research.