CVE-2016-3953: Web2py Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-q2rq-qgcf-m22w
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CVSS 9.8
CWE-798
Published
Advisory Summary

CVE-2016-3953 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-798: Use of Hard-coded Credentials) affecting Web2py libraries in the PyPI ecosystem. The issue involves web2py remote code execution via hardcoded encryption key in session.connect function. Remediation is available by upgrading affected packages to version 2.14.2.

CVE-2016-3953 at a Glance

CVE Identifier CVE-2016-3953
GHSA Identifier GHSA-q2rq-qgcf-m22w
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-798: Use of Hard-coded Credentials
Affected Product Web2py
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2016-3953

To remediate this vulnerability, upgrade all affected Web2py dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

web2py fixed: 2.14.2 
pip install web2py>=2.14.2
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 web2py

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2016-3953, inspect your installed packages using pip:

pip show web2py

Analyze the terminal output to locate any version of Web2py in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.14.2), your application is affected.

Note: The pip show web2py command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-798: Use of Hard-coded Credentials, where the product contains hard-coded credentials, such as a password or cryptographic key. In Web2py, 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

The sample web application in web2py before 2.14.2 might allow remote attackers to execute arbitrary code via vectors involving use of a hardcoded encryption key when calling the `session.connect` function.

CVE-2016-3953 Affected Web2py Versions

1 component(s)
Fixed Versions:
2.14.2
Product / Package Ecosystem Affected Versions Fixed Version
web2py
pypi/web2py
PyPI
< 2.14.2
2.14.2

References

NVD — CVE-2016-3953 NVD
https://nvd.nist.gov/vuln/detail/CVE-2016-3953
Web2py Source Repository REPOSITORY
https://github.com/web2py/web2py/issues/1205
Security Fix Commit FIX COMMIT
https://github.com/web2py/web2py/commit/9706d125b42481178d2b423de245f5d2faadbf40
devco.re/blog/2017/01/03/web... WEB
https://devco.re/blog/2017/01/03/web2py-unserialize-code-execution-CVE-2016-3957
Web2py Source Repository REPOSITORY
https://github.com/web2py/web2py
Web2py Source Repository REPOSITORY
https://github.com/web2py/web2py/blob/R-2.14.1/applications/examples/models/session.py
usn.ubuntu.com/4030-1 WEB
https://usn.ubuntu.com/4030-1

Frequently Asked Questions

What is CVE-2016-3953?
CVE-2016-3953 is a security vulnerability in Web2py involving web2py remote code execution via hardcoded encryption key in session.connect function under CWE-798: Use of Hard-coded Credentials.
Which Web2py versions are affected?
Affected versions include releases prior to 2.14.2 across affected packages: web2py.
What version fixes CVE-2016-3953?
Upgrading to 2.14.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is web2py affected?
Yes, web2py is affected in releases prior to 2.14.2. Upgrade your dependency to 2.14.2 or later.
What is the CVSS score of CVE-2016-3953?
CVE-2016-3953 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2016-3953?
CVE-2016-3953 is classified under CWE-798: Use of Hard-coded Credentials (The product contains hard-coded credentials, such as a password or cryptographic key.).
How can I check PyPI dependencies for CVE-2016-3953?
Run the dependency tree command: 'pip show web2py'. 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-q2rq-qgcf-m22w",
  "modified" : "2023-08-03T22:44:35Z",
  "published" : "2022-05-14T00:57:47Z",
  "aliases" : [ "CVE-2016-3953" ],
  "summary" : "web2py remote code execution via hardcoded encryption key in session.connect function",
  "details" : "The sample web application in web2py before 2.14.2 might allow remote attackers to execute arbitrary code via vectors involving use of a hardcoded encryption key when calling the `session.connect` function.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "web2py"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.14.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2016-3953"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/web2py/web2py/issues/1205"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/web2py/web2py/commit/9706d125b42481178d2b423de245f5d2faadbf40"
  }, {
    "type" : "WEB",
    "url" : "https://devco.re/blog/2017/01/03/web2py-unserialize-code-execution-CVE-2016-3957"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/web2py/web2py"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/web2py/web2py/blob/R-2.14.1/applications/examples/models/session.py"
  }, {
    "type" : "WEB",
    "url" : "https://usn.ubuntu.com/4030-1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-798" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-08-03T22:44:35Z",
    "nvd_published_at" : "2018-02-06T18:29:00Z"
  }
}