Summary

TDengine DataBase crashes on UDF nested query.

Details

The prerequisite are :

• User can connect to db
• User have create function privilege

Whatever the {FILE} content is ok when create udf. Make sure {FILE} is exist on client local.
Actually, Attacker can create a craft request and make {FILE} payload is anything.

PoC

Test on docker image tdengine/tdengine:3.0.4.2 and tdengine/tdengine-amd64:3.0.5.0

taos> create function blah AS '/etc/hosts' outputtype int; 

taos> select blah(n) from (select 1 n)x;

After running this, db crashed, docker container exited.

Impact

This is an Denial-of-Service vulnerability.
It affects TDengine Database which let user connect and run arbitrary queries.

Add on Jun 13th, 2023

I notice that TDEngine does not setup Security Policy. As vulnerability reporter, I will refer to the Github Security Advisories Vulnerability Disclosure Policy to arrange follow-up activities. Show as below.

Disclosure policy
Last updated: November 10th, 2021

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If the project team responds and agrees the issue poses a security risk, we will work with the project security team or maintainers to communicate the vulnerability in detail, and agree on the process for public disclosure. Responsibility for developing and releasing a patch lies firmly with the project team, though we aim to facilitate this by providing detailed information about the vulnerability.

Our disclosure deadline for publicly disclosing a vulnerability is: 90 days after the first report to the project team.

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