CVE-2020-27197: Libtaxii Libtaxii Server-Side Request Forgery Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-836c-xg97-8p4h
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CVSS 9.8
CWE-918
Published
Advisory Summary

CVE-2020-27197 is a CRITICAL (CVSS 9.8) libtaxii server-side request forgery vulnerability vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Libtaxii libraries in the PyPI ecosystem. The issue involves libtaxii server-side request forgery vulnerability. Remediation is available by upgrading affected packages to version 1.1.118.

CVE-2020-27197 at a Glance

CVE Identifier CVE-2020-27197
GHSA Identifier GHSA-836c-xg97-8p4h
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-918: Server-Side Request Forgery (SSRF)
Affected Product Libtaxii
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-2020-27197

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

libtaxii fixed: 1.1.118 
pip install libtaxii>=1.1.118
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 libtaxii

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2020-27197, inspect your installed packages using pip:

pip show libtaxii

Analyze the terminal output to locate any version of Libtaxii in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.1.118), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-918: Server-Side Request Forgery (SSRF), where the web server receives a url or similar request from an upstream component and retrieves the contents of this url, but it does not sufficiently ensure that the request is being sent to the expected destination. In Libtaxii, 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

"TAXII libtaxii through 1.1.117, as used in EclecticIQ OpenTAXII through 0.2.0 and other products, allows SSRF via an initial http:// substring to the parse method, even when the no_network setting is used for the XML parser. NOTE: the vendor points out that the parse method "wraps the lxml library" and that this may be an issue to "raise ... to the lxml group.""

CVE-2020-27197 Affected Libtaxii Versions

1 component(s)
Fixed Versions:
1.1.118
Product / Package Ecosystem Affected Versions Fixed Version
libtaxii
pypi/libtaxii
PyPI
< 1.1.118
1.1.118

References

NVD — CVE-2020-27197 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-27197
Libtaxii Source Repository REPOSITORY
https://github.com/TAXIIProject/libtaxii/issues/246
Libtaxii Source Repository REPOSITORY
https://github.com/eclecticiq/OpenTAXII/issues/176
Libtaxii Source Repository REPOSITORY
https://github.com/TAXIIProject/libtaxii/pull/247
Security Fix Commit FIX COMMIT
https://github.com/TAXIIProject/libtaxii/commit/23c6f7b69d99e965c8d53dc4710ae64da3fb4842
Libtaxii Source Repository REPOSITORY
https://github.com/TAXIIProject/libtaxii
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-836c-xg97-8p4h
Libtaxii Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/libtaxii/PYSEC-2020-59.yaml
Libtaxii Security Information SECURITY
http://packetstormsecurity.com/files/159662/Libtaxii-1.1.117-OpenTaxi-0.2.0-Server-Side-Request-Forgery.html

Frequently Asked Questions

What is CVE-2020-27197?
CVE-2020-27197 is a security vulnerability in Libtaxii involving libtaxii Server-Side Request Forgery vulnerability under CWE-918: Server-Side Request Forgery (SSRF).
Which Libtaxii versions are affected?
Affected versions include releases prior to 1.1.118 across affected packages: libtaxii.
What version fixes CVE-2020-27197?
Upgrading to 1.1.118 (or the latest patched release for your respective branch) resolves the vulnerability.
Is libtaxii affected?
Yes, libtaxii is affected in releases prior to 1.1.118. Upgrade your dependency to 1.1.118 or later.
What is the CVSS score of CVE-2020-27197?
CVE-2020-27197 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-2020-27197?
CVE-2020-27197 is classified under CWE-918: Server-Side Request Forgery (SSRF) (The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.).
How can I check PyPI dependencies for CVE-2020-27197?
Run the dependency tree command: 'pip show libtaxii'. 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-836c-xg97-8p4h",
  "modified" : "2024-09-27T21:39:29Z",
  "published" : "2021-04-30T17:34:48Z",
  "aliases" : [ "CVE-2020-27197" ],
  "summary" : "libtaxii Server-Side Request Forgery vulnerability",
  "details" : "\"TAXII libtaxii through 1.1.117, as used in EclecticIQ OpenTAXII through 0.2.0 and other products, allows SSRF via an initial http:// substring to the parse method, even when the no_network setting is used for the XML parser. NOTE: the vendor points out that the parse method \"wraps the lxml library\" and that this may be an issue to \"raise ... to the lxml group.\"\"",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "libtaxii"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.1.118"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-27197"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TAXIIProject/libtaxii/issues/246"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/eclecticiq/OpenTAXII/issues/176"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TAXIIProject/libtaxii/pull/247"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TAXIIProject/libtaxii/commit/23c6f7b69d99e965c8d53dc4710ae64da3fb4842"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/TAXIIProject/libtaxii"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-836c-xg97-8p4h"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/libtaxii/PYSEC-2020-59.yaml"
  }, {
    "type" : "WEB",
    "url" : "http://packetstormsecurity.com/files/159662/Libtaxii-1.1.117-OpenTaxi-0.2.0-Server-Side-Request-Forgery.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-20T17:53:43Z",
    "nvd_published_at" : "2020-10-17T20:15:00Z"
  }
}