CVE-2016-8638: Ipsilon Session Fixation Vulnerability

CRITICAL
Advisory Identifier: GHSA-376m-3rm2-9jm6
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CVSS 9.1
CWE-384
Published
Advisory Summary

CVE-2016-8638 is a CRITICAL (CVSS 9.1) session fixation vulnerability (CWE-384: Session Fixation) affecting Ipsilon libraries in the PyPI ecosystem. The issue involves session fixation in ipsilon. Remediation is available by upgrading affected packages to version 2.0.2, 1.2.1, 1.1.2, 1.0.3.

CVE-2016-8638 at a Glance

CVE Identifier CVE-2016-8638
GHSA Identifier GHSA-376m-3rm2-9jm6
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-384: Session Fixation
Affected Product Ipsilon
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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 High (C:H)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2016-8638

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

ipsilon fixed: 2.0.2 
pip install ipsilon>=2.0.2
ipsilon fixed: 1.2.1 
pip install ipsilon>=1.2.1
ipsilon fixed: 1.1.2 
pip install ipsilon>=1.1.2
ipsilon fixed: 1.0.3 
pip install ipsilon>=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 ipsilon

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2016-8638, inspect your installed packages using pip:

pip show ipsilon

Analyze the terminal output to locate any version of Ipsilon in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.2), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-384: Session Fixation, where authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions. In Ipsilon, 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

A vulnerability in ipsilon 2.0 before 2.0.2, 1.2 before 1.2.1, 1.1 before 1.1.2, and 1.0 before 1.0.3 was found that allows attacker to log out active sessions of other users. This issue is related to how it tracks sessions, and allows an unauthenticated attacker to view and terminate active sessions from other users. It is also called a "SAML2 multi-session vulnerability."

CVE-2016-8638 Affected Ipsilon Versions

4 component(s)
Fixed Versions:
2.0.21.2.11.1.21.0.3
Product / Package Ecosystem Affected Versions Fixed Version
ipsilon
pypi/ipsilon
PyPI
≥ 2.0.0
< 2.0.2
2.0.2
ipsilon
pypi/ipsilon
PyPI
≥ 1.2.0
< 1.2.1
1.2.1
ipsilon
pypi/ipsilon
PyPI
≥ 1.1.0
< 1.1.2
1.1.2
ipsilon
pypi/ipsilon
PyPI
≥ 1.0.0
< 1.0.3
1.0.3

References

NVD — CVE-2016-8638 NVD
https://nvd.nist.gov/vuln/detail/CVE-2016-8638
Security Fix Commit FIX COMMIT
https://github.com/ipsilon-project/ipsilon/commit/1c48414877fc110652b6078a29529972c7ec9122
Security Fix Commit FIX COMMIT
https://github.com/ipsilon-project/ipsilon/commit/64fc366c054fc6af1d9d2692902db169884b5f78
Security Fix Commit FIX COMMIT
https://github.com/ipsilon-project/ipsilon/commit/a33303b6beb5c316d7c18b23566b7666a4e307a4
Security Fix Commit FIX COMMIT
https://github.com/ipsilon-project/ipsilon/commit/b4744a92d4fa7f6d7ade0ae2d99a2dc0ea94734d
access.redhat.com/errata/rhsa-2016:28... WEB
https://access.redhat.com/errata/RHSA-2016:2809
Ipsilon Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2016-8638
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=1392829
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8638
Ipsilon Source Repository REPOSITORY
https://github.com/ipsilon-project/ipsilon
Ipsilon Security Information SECURITY
https://ipsilon-project.org/advisory/CVE-2016-8638.txt
Ipsilon Release RELEASE
https://ipsilon-project.org/release/2.1.0.html
pagure.io/ipsilon/c/511fa8b70... WEB
https://pagure.io/ipsilon/c/511fa8b7001c2f9a42301aa1d4b85aaf170a461c
rhn.redhat.com/errata/rhsa-2016-28... WEB
http://rhn.redhat.com/errata/RHSA-2016-2809.html
Ipsilon Security Information SECURITY
http://www.securityfocus.com/bid/94439

Frequently Asked Questions

What is CVE-2016-8638?
CVE-2016-8638 is a security vulnerability in Ipsilon involving Session Fixation in ipsilon under CWE-384: Session Fixation.
Which Ipsilon versions are affected?
Affected versions include releases prior to 2.0.2, 1.2.1, 1.1.2, 1.0.3 across affected packages: ipsilon.
What version fixes CVE-2016-8638?
Upgrading to 2.0.2, 1.2.1, 1.1.2, 1.0.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ipsilon affected?
Yes, ipsilon is affected in releases prior to 2.0.2, 1.2.1, 1.1.2, 1.0.3. Upgrade your dependency to 2.0.2, 1.2.1, 1.1.2, 1.0.3 or later.
What is the CVSS score of CVE-2016-8638?
CVE-2016-8638 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
What CWE is associated with CVE-2016-8638?
CVE-2016-8638 is classified under CWE-384: Session Fixation (Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.).
How can I check PyPI dependencies for CVE-2016-8638?
Run the dependency tree command: 'pip show ipsilon'. 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-376m-3rm2-9jm6",
  "modified" : "2023-02-14T00:46:20Z",
  "published" : "2022-05-14T03:55:23Z",
  "aliases" : [ "CVE-2016-8638" ],
  "summary" : "Session Fixation in ipsilon",
  "details" : "A vulnerability in ipsilon 2.0 before 2.0.2, 1.2 before 1.2.1, 1.1 before 1.1.2, and 1.0 before 1.0.3 was found that allows attacker to log out active sessions of other users.  This issue is related to how it tracks sessions, and allows an unauthenticated attacker to view and terminate active sessions from other users. It is also called a \"SAML2 multi-session vulnerability.\"",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ipsilon"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.0.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ipsilon"
    },
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      }, {
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      } ]
    } ]
  }, {
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    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.1.0"
      }, {
        "fixed" : "1.1.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ipsilon"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
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        "introduced" : "1.0.0"
      }, {
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      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2016-8638"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ipsilon-project/ipsilon/commit/1c48414877fc110652b6078a29529972c7ec9122"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ipsilon-project/ipsilon/commit/64fc366c054fc6af1d9d2692902db169884b5f78"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ipsilon-project/ipsilon/commit/a33303b6beb5c316d7c18b23566b7666a4e307a4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ipsilon-project/ipsilon/commit/b4744a92d4fa7f6d7ade0ae2d99a2dc0ea94734d"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2016:2809"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2016-8638"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1392829"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-8638"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ipsilon-project/ipsilon"
  }, {
    "type" : "WEB",
    "url" : "https://ipsilon-project.org/advisory/CVE-2016-8638.txt"
  }, {
    "type" : "WEB",
    "url" : "https://ipsilon-project.org/release/2.1.0.html"
  }, {
    "type" : "WEB",
    "url" : "https://pagure.io/ipsilon/c/511fa8b7001c2f9a42301aa1d4b85aaf170a461c"
  }, {
    "type" : "WEB",
    "url" : "http://rhn.redhat.com/errata/RHSA-2016-2809.html"
  }, {
    "type" : "WEB",
    "url" : "http://www.securityfocus.com/bid/94439"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-384" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-02-14T00:46:20Z",
    "nvd_published_at" : "2017-07-12T13:29:00Z"
  }
}