Patchfirst
CVE-2018-15133 KEVPublic exploit High · 8.1 EPSS 76.6%

Laravel Deserialization of Untrusted Data Vulnerability

Laravel · Laravel Framework

Summary

Laravel Framework versions through 5.5.40 and 5.6.x through 5.6.29 contain a deserialization flaw, where an unserialize call on the X-XSRF-TOKEN value in the decrypt method of Illuminate/Encryption/Encrypter.php can be abused for remote code execution. An attacker would need network access and knowledge of the application key, which they would typically only obtain through prior privileged access or a previous successful attack, and no authentication or user interaction is required.

Official description · NVD

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. 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.

Breakdown
68.6 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
2/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited 5 years after disclosure. Public exploit code (Metasploit) was available 2 days before disclosure.

  1. Public exploit codeMetasploit2 days before
  2. Disclosedday 0
  3. First seen exploitedVulnCheck KEV evidence+5 yrs
  4. Added to CISA KEVEU database agrees+5 yrs

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Exploit Public-Facing Application T1190 Medium
AI mapping from the description · how it is exploited

Remote attack via public-facing web application input

remote code execution might occur as a result of an unserialize call on a potentially untrusted X-XSRF-TOKEN value
From the official description (NVD) Original (opens in a new tab) ↗

ExecutionTA0002

Command and Scripting Interpreter T1059 Medium
AI mapping from the description · primary impact

Unserialize yields arbitrary code execution

remote code execution might occur as a result of an unserialize call
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 244 general rules for its techniques

Rules for this CVE

0 that reference CVE-2018-15133 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

Am I affected? What do I upgrade to?

From GitHub Security Advisories and OSV

1 package in 1 ecosystem. Main package: laravel/framework.

Packagistlaravel/frameworkGHSA-qvqm-h22r-4cp9

Upgrade to 5.6.30

Still affected on this line by CVE-2024-52301 (fixed in 6.20.45, a newer line); CVE-2026-114509 (fixed in 12.68.0, a newer line).

Set the version to 5.6.30 or later in your composer.json.

The first fix for CVE-2018-15133.

Affected versions, by release line

If you runUpgrade to
5.6.0 up to 5.6.305.6.30
5.5.40 and earlierNo fix published

“Up to” means the second version is the fix and is not affected.

Check your lockfile against all CVEs

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

3 links, grouped by NVD tag (2 duplicates merged)
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