GHSA-ppgf-8745-8pgx
Insecure Deserialization & Arbitrary Code Execution in TYPO3 CMS
- Severity
- High
- The publisher's own rating, not a CVSS score
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-502 Deserialization of Untrusted Data
- Fix
7.6.30- Upgrade typo3/cms to this version or later
Description
Phar files (formerly known as "PHP archives") can act als self extracting archives which leads to the fact that source code is executed when Phar files are invoked. The Phar file format is not limited to be stored with a dedicated file extension - "bundle.phar" would be valid as well as "bundle.txt" would be. This way, Phar files can be obfuscated as image or text file which would not be denied from being uploaded and persisted to a TYPO3 installation. Due to a missing sanitization of user input, those Phar files can be invoked by manipulated URLs in TYPO3 backend forms. A valid backend user account is needed to exploit this vulnerability. In theory the attack vector would be possible in the TYPO3 frontend as well, however no functional exploit has been identified so far.
Affected versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| typo3/cms | >= 7.0.0, < 7.6.30 |
7.6.30 |
| typo3/cms | >= 8.0.0, < 8.7.17 |
8.7.17 |
| typo3/cms | >= 9.0.0, < 9.3.2 |
9.3.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
typo3/cms Packagist → 7.6.30
- composer
composer require typo3/cms:^7.6.30
Weakness
CWE-502: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How to prevent it
- Architecture and Design, Implementation: If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- Implementation: When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Implementation: Explicitly define a final object() to prevent deserialization.
- Architecture and Design, Implementation: Make fields transient to protect them from deserialization. An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.
- Implementation: Avoid having unnecessary types or gadgets (a sequence of instances and method invocations that can self-execute during the deserialization process, often found in libraries) available that can be leveraged for malicious ends. This limits the potential for unintended or unauthorized types and gadgets to be leveraged by the attacker. Add only acceptable classes to an allowlist. Note: new gadgets are constantly being discovered, so this alone is not a sufficient mitigation.
- Architecture and Design, Implementation: Employ cryptography of the data or code for protection. However, it's important to note that it would still be client-side security. This is risky because if the client is compromised then the security implemented on the client (the cryptography) can be bypassed.
- Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].
References
Other links
Timeline
- Published
- Last updated by the source
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-f3wf-q4fj-3gxf TYPO3 Denial of Service in Online Media Asset Handling | Medium | Also affects typo3/cms |
| GHSA-6487-3qvg-8px9 TYPO3 Information Disclosure in Install Tool | Medium | Also affects typo3/cms |
| GHSA-f777-f784-36gm TYPO3 Security Misconfiguration in Install Tool Cookie | High | Also affects typo3/cms |
| GHSA-2rcw-9hrm-8q7q TYPO3 Cross-Site Scripting in Frontend User Login | Medium | Also affects typo3/cms |
| GHSA-7q33-hxwj-7p8v TYPO3 Cross-Site Scripting in Backend Modal Component | Medium | Also affects typo3/cms |
| GHSA-8m6j-p5jv-v69w TYPO3 Cross-Site Scripting in Online Media Asset Rendering | Medium | Also affects typo3/cms |
| GHSA-8h4m-r4wm-xj7r TYPO3 Arbitrary Code Execution via File List Module | High | Also affects typo3/cms |
| GHSA-g585-crjf-vhwq TYPO3 Denial of Service in Frontend Record Registration | High | Also affects typo3/cms |
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