CVE-2018-15133
Laravel Deserialization of Untrusted Data Vulnerability
Laravel Framework
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 16 January 2024. US federal agencies were required to remediate it by 6 February 2024.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 76.6%, which is higher than 99.5% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2018-15133 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2018-15133.
What does CVE-2018-15133 affect?
CVE-2018-15133 affects Laravel Framework. 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.
How severe is CVE-2018-15133?
CVE-2018-15133 is rated HIGH with a CVSS base score of 8.1. EPSS puts the probability of exploitation in the next 30 days at 76.6%, higher than 99.5% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 6 February 2024.
How should organisations respond to CVE-2018-15133?
Apply the vendor patch for Laravel Framework as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.