GHSA-hh95-5xm5-v8v7 TYPO3 CMS Possible Insecure Deserialization in Extbase Request Handling
Attackers with a leaked encryption key can exploit insecure deserialization in TYPO3 Extbase to execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-hh95-5xm5-v8v7?
GHSA-hh95-5xm5-v8v7 is an unsafe deserialization vulnerability in typo3/cms, published on 7 Jun 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
It has been discovered that request handling in Extbase can be vulnerable to insecure deserialization. User submitted payload has to be signed with a corresponding HMAC-SHA1 using the sensitive TYPO3 encryptionKey as secret - invalid or unsigned payload is not deserialized.
However, since sensitive information could have been leaked by accident (e.g. in repositories or in commonly known and unprotected backup files), there is the possibility that attackers know the private encryptionKey and are able to calculate the required HMAC-SHA1 to allow a malicious payload to be deserialized.
Requirements for successfully exploiting this vulnerability (all of the following):
- rendering at least one Extbase plugin in the frontend
- encryptionKey has been leaked (from LocalConfiguration.php or corresponding .env file)
Which versions are affected by GHSA-hh95-5xm5-v8v7?
4 open source packages ship an affected version, including typo3/cms.
| Package | Affected | Fixed in |
|---|---|---|
typo3/cms Packagist | From 8.0.0 | 8.7.30 |
typo3/cms Packagist | From 8.0.0 | 8.7.30 |
typo3/cms Packagist | From 9.0.0 | 9.5.12 |
typo3/cms Packagist | From 9.0.0 | 9.5.12 |
How do I fix GHSA-hh95-5xm5-v8v7?
Upgrade typo3/cms to a fixed version for your release line: 8.7.30 or 9.5.12.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is GHSA-hh95-5xm5-v8v7 being exploited?
There is no known exploitation of GHSA-hh95-5xm5-v8v7 in the wild and no public exploit code.