CVE-2018-15133
RCE in Laravel ≤ 5.5.40
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2018-15133 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Laravel Laravel. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 0.5% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2018-15133 affects the Laravel Framework through version 5.5.40 and 5.6.x through 5.6.29. It stems from unsafe handling of the X-XSRF-TOKEN header, where the decrypt method in Illuminate/Encryption/Encrypter.php performs an unserialize operation on attacker-supplied data. This enables use of known gadget chains, such as the one in phpggc for Laravel RCE, when the application key is known.
An attacker with knowledge of the application key can supply a crafted token to trigger remote code execution. The key requirement implies the attacker must have obtained it through prior privileged access or a separate compromise, after which the deserialization flaw allows arbitrary code execution with the privileges of the web application process.
Laravel addressed the issue by releasing version 5.6.30 and corresponding patches for the 5.5 branch, as documented in the framework upgrade notes. The vulnerability is also catalogued in CISA's known exploited vulnerabilities list, confirming observed in-the-wild activity.
Public exploit code has been published on PacketStorm, demonstrating practical weaponization of the deserialization path once the application key is obtained.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-5039
Vulnerability Data
In Laravel Framework through 5.5.40 and 5.6.x through 5.6.29, remote code execution might occur as a result of an unserialize call on a potentially untrusted X-XSRF-TOKEN value. This involves the decrypt method in Illuminate/Encryption/Encrypter.php and PendingBroadcast in gadgetchains/Laravel/RCE/3/chain.php in phpggc.…
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The attacker must know the application key, which normally would never occur, but could happen if the attacker previously had privileged access or successfully accomplished a previous attack.
- CWE(s)
- KEV Date Added
- 16 January 2024
Related Threats
Threat-Actor AttributionAI
MITRE ATT&CK Enterprise Techniques
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Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.
Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.
Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.
Validates or rejects untrusted serialized data before deserialization occurs.
Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.
Integrity verification of serialized information can detect tampering before deserialization occurs.
Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.