CVE-2023-27891: Pretix Insufficient Session Expiration Vulnerability

HIGH
Advisory Identifier: GHSA-r76w-3wwq-jv6v
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CVSS 7.5
CWE-613
Published
Advisory Summary

CVE-2023-27891 is a HIGH (CVSS 7.5) insufficient session expiration vulnerability (CWE-613: Insufficient Session Expiration) affecting Pretix libraries in the PyPI ecosystem. The issue involves insufficient session expiration in pretix. Remediation is available by upgrading affected packages to version 4.17.1, 4.16.1, 4.15.1.

CVE-2023-27891 at a Glance

CVE Identifier CVE-2023-27891
GHSA Identifier GHSA-r76w-3wwq-jv6v
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-613: Insufficient Session Expiration
Affected Product Pretix
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:H/I:N/A:N).

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 None (I:N)
Availability None (A:N)

How to Fix CVE-2023-27891

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

pretix fixed: 4.17.1 
pip install pretix>=4.17.1
pretix fixed: 4.16.1 
pip install pretix>=4.16.1
pretix fixed: 4.15.1 
pip install pretix>=4.15.1
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 pretix

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-27891, inspect your installed packages using pip:

pip show pretix

Analyze the terminal output to locate any version of Pretix in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.17.1), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-613: Insufficient Session Expiration, where according to wasc, "insufficient session expiration is when a web site permits an attacker to reuse old session credentials or session ids for authorization.". In Pretix, 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

rami.io pretix before 4.17.1 allows OAuth application authorization from a logged-out session. The fixed versions are 4.15.1, 4.16.1, and 4.17.1.

CVE-2023-27891 Affected Pretix Versions

3 component(s)
Fixed Versions:
4.17.14.16.14.15.1
Product / Package Ecosystem Affected Versions Fixed Version
pretix
pypi/pretix
PyPI
≥ 4.17.0
< 4.17.1
4.17.1
pretix
pypi/pretix
PyPI
≥ 4.16.0
< 4.16.1
4.16.1
pretix
pypi/pretix
PyPI
< 4.15.1
4.15.1

References

NVD — CVE-2023-27891 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-27891
Pretix Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/pretix/PYSEC-2023-42.yaml
Pretix Source Repository REPOSITORY
https://github.com/thufschmitt/pretix-nix
Pretix Release RELEASE
https://pretix.eu/about/en/blog/20230306-release-4171

Frequently Asked Questions

What is CVE-2023-27891?
CVE-2023-27891 is a security vulnerability in Pretix involving Insufficient Session Expiration in pretix under CWE-613: Insufficient Session Expiration.
Which Pretix versions are affected?
Affected versions include releases prior to 4.17.1, 4.16.1, 4.15.1 across affected packages: pretix.
What version fixes CVE-2023-27891?
Upgrading to 4.17.1, 4.16.1, 4.15.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pretix affected?
Yes, pretix is affected in releases prior to 4.17.1, 4.16.1, 4.15.1. Upgrade your dependency to 4.17.1, 4.16.1, 4.15.1 or later.
What is the CVSS score of CVE-2023-27891?
CVE-2023-27891 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:H/I:N/A:N.
What CWE is associated with CVE-2023-27891?
CVE-2023-27891 is classified under CWE-613: Insufficient Session Expiration (According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.").
How can I check PyPI dependencies for CVE-2023-27891?
Run the dependency tree command: 'pip show pretix'. 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-r76w-3wwq-jv6v",
  "modified" : "2024-10-21T19:57:52Z",
  "published" : "2023-03-07T00:30:24Z",
  "aliases" : [ "CVE-2023-27891" ],
  "summary" : "Insufficient Session Expiration in pretix",
  "details" : "rami.io pretix before 4.17.1 allows OAuth application authorization from a logged-out session. The fixed versions are 4.15.1, 4.16.1, and 4.17.1.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pretix"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.17.0"
      }, {
        "fixed" : "4.17.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pretix"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.16.0"
      }, {
        "fixed" : "4.16.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pretix"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.15.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-27891"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pretix/PYSEC-2023-42.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/thufschmitt/pretix-nix"
  }, {
    "type" : "WEB",
    "url" : "https://pretix.eu/about/en/blog/20230306-release-4171"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-613" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-14T23:01:26Z",
    "nvd_published_at" : "2023-03-06T23:15:00Z"
  }
}