CVE-2021-41499: Pyo Classic Buffer Overflow Vulnerability

HIGH
Advisory Identifier: GHSA-5f5c-687x-g5qm
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CVSS 7.5
CWE-120
Published
Advisory Summary

CVE-2021-41499 is a HIGH (CVSS 7.5) classic buffer overflow vulnerability (CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')) affecting Pyo libraries in the PyPI ecosystem. The issue involves classic buffer overflow in pyo. Remediation is available by upgrading affected packages to version 1.0.3.

CVE-2021-41499 at a Glance

CVE Identifier CVE-2021-41499
GHSA Identifier GHSA-5f5c-687x-g5qm
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Affected Product Pyo
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-41499

To remediate this vulnerability, upgrade all affected Pyo dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pyo fixed: 1.0.3 
pip install pyo>=1.0.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pyo

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2021-41499, inspect your installed packages using pip:

pip show pyo

Analyze the terminal output to locate any version of Pyo in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.3), your application is affected.

Note: The pip show pyo command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'), where the product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer. In Pyo, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Buffer Overflow Vulnerability exists in ajaxsoundstudio.com in Pyo < 1.03 in the Server_debug function, which allows remote attackers to conduct DoS attacks by deliberately passing on an overlong audio file name.

CVE-2021-41499 Affected Pyo Versions

1 component(s)
Fixed Versions:
1.0.3
Product / Package Ecosystem Affected Versions Fixed Version
pyo
pypi/pyo
PyPI
< 1.0.3
1.0.3

References

NVD — CVE-2021-41499 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-41499
Pyo Source Repository REPOSITORY
https://github.com/belangeo/pyo/issues/222
Pyo Source Repository REPOSITORY
https://github.com/belangeo/pyo

Frequently Asked Questions

What is CVE-2021-41499?
CVE-2021-41499 is a security vulnerability in Pyo involving Classic Buffer Overflow in pyo under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow').
Which Pyo versions are affected?
Affected versions include releases prior to 1.0.3 across affected packages: pyo.
What version fixes CVE-2021-41499?
Upgrading to 1.0.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pyo affected?
Yes, pyo is affected in releases prior to 1.0.3. Upgrade your dependency to 1.0.3 or later.
What is the CVSS score of CVE-2021-41499?
CVE-2021-41499 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-41499?
CVE-2021-41499 is classified under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') (The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.).
How can I check PyPI dependencies for CVE-2021-41499?
Run the dependency tree command: 'pip show pyo'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5f5c-687x-g5qm",
  "modified" : "2022-01-06T18:52:40Z",
  "published" : "2022-01-07T00:10:33Z",
  "aliases" : [ "CVE-2021-41499" ],
  "summary" : "Classic Buffer Overflow in pyo",
  "details" : "Buffer Overflow Vulnerability exists in ajaxsoundstudio.com in Pyo < 1.03 in the Server_debug function, which allows remote attackers to conduct DoS attacks by deliberately passing on an overlong audio file name.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pyo"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-41499"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/belangeo/pyo/issues/222"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/belangeo/pyo"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-120" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-01-06T18:52:40Z",
    "nvd_published_at" : "2021-12-17T21:15:00Z"
  }
}