CVE-2018-16831: Smarty/smarty Path Traversal Vulnerability

MODERATE
Advisory Identifier: GHSA-65j5-vpm7-6xp4
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CVSS 5.9
CWE-22
Published
Advisory Summary

CVE-2018-16831 is a MODERATE (CVSS 5.9) path traversal vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Smarty/smarty libraries in the Packagist ecosystem. The issue involves smarty path traversal vulnerability. Remediation is available by upgrading affected packages to version 3.1.33.

CVE-2018-16831 at a Glance

CVE Identifier CVE-2018-16831
GHSA Identifier GHSA-65j5-vpm7-6xp4
Severity MODERATE
CVSS v3.1 Base Score 5.9
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Smarty/smarty
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 5.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
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-2018-16831

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

smarty/smarty fixed: 3.1.33 
Upgrade smarty/smarty to 3.1.33
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 smarty/smarty

How to Check if You Are Affected

To determine whether your application is affected by CVE-2018-16831, inspect your project dependencies for Smarty/smarty:

inspect dependencies for smarty/smarty

Analyze the terminal output to locate any version of Smarty/smarty in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.1.33), 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-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Smarty/smarty, 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

Smarty before 3.1.33-dev-4 allows attackers to bypass the trusted_dir protection mechanism via a `file:./../` substring in an include statement.

CVE-2018-16831 Affected Smarty/smarty Versions

1 component(s)
Fixed Versions:
3.1.33
Product / Package Ecosystem Affected Versions Fixed Version
smarty/smarty
 Packagist
< 3.1.33
3.1.33

References

NVD — CVE-2018-16831 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-16831
Smarty/smarty Source Repository REPOSITORY
https://github.com/smarty-php/smarty/issues/486
Security Fix Commit FIX COMMIT
https://github.com/smarty-php/smarty/commit/f9ca3c63d1250bb56b2bda609dcc9dd81f0065f8
Smarty/smarty Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/smarty/smarty/CVE-2018-16831.yaml
Smarty/smarty Source Repository REPOSITORY
https://github.com/smarty-php/smarty

Frequently Asked Questions

What is CVE-2018-16831?
CVE-2018-16831 is a security vulnerability in Smarty/smarty involving Smarty Path Traversal Vulnerability under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Smarty/smarty versions are affected?
Affected versions include releases prior to 3.1.33 across affected packages: smarty/smarty.
What version fixes CVE-2018-16831?
Upgrading to 3.1.33 (or the latest patched release for your respective branch) resolves the vulnerability.
Is smarty/smarty affected?
Yes, smarty/smarty is affected in releases prior to 3.1.33. Upgrade your dependency to 3.1.33 or later.
What is the CVSS score of CVE-2018-16831?
CVE-2018-16831 has a CVSS v3.1 base score of 5.9 (MODERATE) with vector string CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2018-16831?
CVE-2018-16831 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check Packagist dependencies for CVE-2018-16831?
Run the dependency tree command: 'inspect dependencies for smarty/smarty'. 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-65j5-vpm7-6xp4",
  "modified" : "2023-10-06T17:44:26Z",
  "published" : "2022-05-14T01:58:46Z",
  "aliases" : [ "CVE-2018-16831" ],
  "summary" : "Smarty Path Traversal Vulnerability",
  "details" : "Smarty before 3.1.33-dev-4 allows attackers to bypass the trusted_dir protection mechanism via a `file:./../` substring in an include statement.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "smarty/smarty"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.33"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-16831"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/smarty-php/smarty/issues/486"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/smarty-php/smarty/commit/f9ca3c63d1250bb56b2bda609dcc9dd81f0065f8"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/smarty/smarty/CVE-2018-16831.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/smarty-php/smarty"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-07-25T19:37:36Z",
    "nvd_published_at" : "2018-09-11T13:29:00Z"
  }
}