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PhpemsApplication

CVE-2023-6654

HIGH · 8.8 CVSS v3.1 Published 2023-12-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability classified as critical was found in PHPEMS 6.x/7.x/8.x/9.0. Affected by this vulnerability is an unknown functionality in the library lib/session.cls.php of the component Session Data Handler. The manipulation leads to deserialization. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-247357 was assigned to this vulnerability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

PHPEMS versions 6.x through 9.0 contain an insecure deserialization vulnerability in the Session Data Handler (lib/session.cls.php). The application deserializes user-controlled session data without proper validation, allowing remote attackers to craft malicious serialized PHP objects that can lead to remote code execution.

MitigationReplace unsafe unserialize() calls with safe alternatives like json_encode/json_decode, or implement whitelisting/validation before deserialization. Additionally, ensure session data storage uses secure, non-deserializable formats.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PhpemsApplication
Affected:= 6.0= 7.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm PHPEMS installation
    Locate the PHPEMS application directory on the server. Look for the presence of the main application files such as index.php or a known PHPEMS configuration file.
    Affected if PHPEMS is installed on the server.
  2. Identify PHPEMS version
    Check the version file or configuration within the PHPEMS installation. Common locations include a version.php file, a config.inc.php file, or the main index.php that may display version information.
    Affected if The installed version falls within 6.x through 9.0 (or specifically 6.0 to 7.0 based on listed affected versions).
  3. Locate vulnerable session handler file
    Verify the presence of the file lib/session.cls.php in the PHPEMS installation directory.
    Affected if The file lib/session.cls.php exists in the PHPEMS installation.
  4. Check for insecure deserialization in session handler
    Open lib/session.cls.php and search for unserialize() function calls. Look for code that deserializes session data, particularly any unserialize() calls that process user-supplied or session-stored data without validation.
    Affected if The file contains unserialize() calls that process session data without prior validation or sanitization.
  5. Verify custom session handling is in use
    Examine the application configuration or bootstrap files to determine if the custom session handler (lib/session.cls.php) is actually being used by the application. Check for code that includes or instantiates the Session class.
    Affected if The application loads and uses the custom Session class from lib/session.cls.php.

A user is affected if PHPEMS versions 6.0 through 9.0 is installed, the file lib/session.cls.php exists with unserialize() calls processing session data, and the custom session handler is actively used by the application.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace unsafe unserialize() calls with safe alternatives like json_encode/json_decode, or implement whitelisting/validation before deserialization. Additionally, ensure session data storage uses secure, non-deserializable formats.

Fix this in Phpems Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-6654 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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