CVE-2019-16993: Phpbb/phpbb PhpBB Cross-Site Request Forgery (CSRF) Vulnerability

HIGH
Advisory Identifier: GHSA-vj3x-vfm4-hvxc
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CVSS 8.8
CWE-352
Published
Advisory Summary

CVE-2019-16993 is a HIGH (CVSS 8.8) phpbb cross-site request forgery (csrf) vulnerability (CWE-352: Cross-Site Request Forgery (CSRF)) affecting Phpbb/phpbb libraries in the Packagist ecosystem. The issue involves phpbb cross-site request forgery (csrf). Remediation is available by upgrading affected packages to version 3.1.7-PL1.

CVE-2019-16993 at a Glance

CVE Identifier CVE-2019-16993
GHSA Identifier GHSA-vj3x-vfm4-hvxc
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-352: Cross-Site Request Forgery (CSRF)
Affected Product Phpbb/phpbb
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.8

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:R/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 Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2019-16993

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

phpbb/phpbb fixed: 3.1.7-PL1 
Upgrade phpbb/phpbb to 3.1.7-PL1
Verify Direct and Transitive Dependencies

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

inspect dependencies for phpbb/phpbb

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-16993, inspect your project dependencies for Phpbb/phpbb:

inspect dependencies for phpbb/phpbb

Analyze the terminal output to locate any version of Phpbb/phpbb in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.1.7-PL1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-352: Cross-Site Request Forgery (CSRF), where the web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor. In Phpbb/phpbb, 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

In phpBB before 3.1.7-PL1, includes/acp/acp_bbcodes.php has improper verification of a CSRF token on the BBCode page in the Administration Control Panel. An actual CSRF attack is possible if an attacker also manages to retrieve the session id of a reauthenticated administrator prior to targeting them.

CVE-2019-16993 Affected Phpbb/phpbb Versions

1 component(s)
Fixed Versions:
3.1.7-PL1
Product / Package Ecosystem Affected Versions Fixed Version
phpbb/phpbb
 Packagist
< 3.1.7-PL1
3.1.7-PL1

References

NVD — CVE-2019-16993 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-16993
Security Fix Commit FIX COMMIT
https://github.com/phpbb/phpbb/commit/18abef716ecf42a35416444f3f84f5459d573789
Phpbb/phpbb Source Repository REPOSITORY
https://github.com/phpbb/phpbb-app
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2019/09/msg00036.html
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2019/10/msg00006.html
www.phpbb.com/community/viewtopic... WEB
https://www.phpbb.com/community/viewtopic.php?t=2352606
www.phpbb.com/support/documents.p... WEB
https://www.phpbb.com/support/documents.php?mode=changelog&version=3#v317

Frequently Asked Questions

What is CVE-2019-16993?
CVE-2019-16993 is a security vulnerability in Phpbb/phpbb involving phpBB Cross-Site Request Forgery (CSRF) under CWE-352: Cross-Site Request Forgery (CSRF).
Which Phpbb/phpbb versions are affected?
Affected versions include releases prior to 3.1.7-PL1 across affected packages: phpbb/phpbb.
What version fixes CVE-2019-16993?
Upgrading to 3.1.7-PL1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is phpbb/phpbb affected?
Yes, phpbb/phpbb is affected in releases prior to 3.1.7-PL1. Upgrade your dependency to 3.1.7-PL1 or later.
What is the CVSS score of CVE-2019-16993?
CVE-2019-16993 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2019-16993?
CVE-2019-16993 is classified under CWE-352: Cross-Site Request Forgery (CSRF) (The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.).
How can I check Packagist dependencies for CVE-2019-16993?
Run the dependency tree command: 'inspect dependencies for phpbb/phpbb'. 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-vj3x-vfm4-hvxc",
  "modified" : "2024-04-24T17:44:43Z",
  "published" : "2022-05-24T16:57:09Z",
  "aliases" : [ "CVE-2019-16993" ],
  "summary" : "phpBB Cross-Site Request Forgery (CSRF)",
  "details" : "In phpBB before 3.1.7-PL1, includes/acp/acp_bbcodes.php has improper verification of a CSRF token on the BBCode page in the Administration Control Panel. An actual CSRF attack is possible if an attacker also manages to retrieve the session id of a reauthenticated administrator prior to targeting them.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "phpbb/phpbb"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.7-PL1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-16993"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/phpbb/phpbb/commit/18abef716ecf42a35416444f3f84f5459d573789"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/phpbb/phpbb-app"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2019/09/msg00036.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2019/10/msg00006.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.phpbb.com/community/viewtopic.php?t=2352606"
  }, {
    "type" : "WEB",
    "url" : "https://www.phpbb.com/support/documents.php?mode=changelog&version=3#v317"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-352" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-24T17:44:43Z",
    "nvd_published_at" : "2019-09-30T12:15:00Z"
  }
}