Security readout for executives and security teams
Plain-English summary
This CVE affects Codeception, a PHP testing package. A class in vulnerable versions can be abused as a deserialization gadget, allowing command execution only when an application already deserializes untrusted input. Treat it seriously where Codeception is installed in reachable runtime environments, but the sources do not show broad active exploitation.
Executive priority
Prioritize remediation for internet-facing PHP services or shared platforms that may deserialize user input and ship development dependencies. For development-only use, schedule prompt dependency updates and confirm the package is excluded from production artifacts.
Technical view
CVE-2021-23420 concerns codeception/codeception versions before 4.1.22 and before 3.1.3. The RunProcess class can be leveraged during unsafe PHP object deserialization to run arbitrary commands. The CVSS 3.1 score is 7.7 with high attack complexity and no privileges or user interaction required.
Likely exposure
Highest exposure is PHP applications where vulnerable Codeception classes are installed and autoloadable in production or other reachable environments that deserialize user-controlled data. Projects using Codeception only as an isolated development dependency have lower practical exposure, but should still update.
Exploitation context
The source bundle includes a public PoC reference and exploit maturity is marked functional, but KEV is false. Active exploitation is not established by the provided sources. Exploitation depends on a separate unsafe deserialization path; the package gadget alone does not prove reachability.
Researcher notes
This is a gadget-chain risk, not evidence of a vulnerable application endpoint by itself. Validation should focus on dependency version, autoload scope, and actual unsafe deserialization paths. Avoid assuming exploitability unless both the gadget and a controllable deserialization sink are present.
Mitigation direction
- Upgrade codeception/codeception to 4.1.22, 3.1.3, or later applicable patched versions.
- Remove Codeception from production deployments when it is only needed for testing.
- Eliminate deserialization of untrusted user input wherever present.
- Check current Codeception vendor guidance before making dependency exceptions.
- Restrict autoloaded development dependencies in runtime build artifacts.
Validation and detection
- Review composer manifests and lockfiles for codeception/codeception versions.
- Confirm whether Codeception is present in production or reachable runtime containers.
- Search application code for unsafe deserialization of user-controlled input.
- Verify patched versions are installed after dependency updates.
- Assess whether vulnerable classes are autoloadable in exposed execution paths.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-23420 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L/E:F/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L/E:F/RL:O/RC:C2.25.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.7HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L/E:F/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/JinYiTong/pocCVE reference · x_refsource_MISC
- https://snyk.io/vuln/SNYK-PHP-CODECEPTIONCODECEPTION-1324585CVE reference · x_refsource_MISC
- https://github.com/Codeception/Codeception/blob/4.1/ext/RunProcess.php%23L52CVE reference · x_refsource_MISC
- https://github.com/Codeception/Codeception/pull/6241CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.