GHSA-mhgm-52vg-pvvc Privilege escalation in Strongbox
An attacker with read-only access can craft valid encrypted secrets to escalate privileges or modify data if write access to storage is also available.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-mhgm-52vg-pvvc?
GHSA-mhgm-52vg-pvvc is a vulnerability in com.schibsted.security:strongbox-sdk, published on 16 Feb 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Impact
An attacker with read-only access to a Strongbox secret could craft a valid encrypted secret (same id/version). It also makes the audit logs from KMS less useful. The issue is caused by a bug in the underlying AWS Encryption SDK.
By default, the encrypted secrets are stored in DynamoDB and an attacker with read-only access would not be able to write the encrypted secret to DynamoDB. So in practice the impact should be limited for most users.
Strongbox supports storing data in files as an alternative to DynamoDB. If the attacker had write access to where the files are stored they could make the attack work end-to-end. Similarly, any custom storage backend could also be affected.
In order to be backwards compatible Strongbox will not make use of key commitments (another improvement to the AWS Encryption SDK). Strongbox enforces that only one KMS key can be used, and it must match the expected one. This means that an attacker needs write access to both KMS and DynamoDB (or other storage backend) to stage an attack, which is not a scenario Strongbox is designed to protect against.
Patches
Fixed in version 0.5.0.
Workarounds
None
References
Which versions are affected by GHSA-mhgm-52vg-pvvc?
2 open source packages ship an affected version, including com.schibsted.security:strongbox-sdk.
| Package | Affected | Fixed in |
|---|---|---|
com.schibsted.security:strongbox-sdk Maven | All versions | 0.5.0 |
com.schibsted.security:strongbox-sdk Maven | All versions | 0.5.0 |
How do I fix GHSA-mhgm-52vg-pvvc?
Upgrade com.schibsted.security:strongbox-sdk to 0.5.0 or later.
Is GHSA-mhgm-52vg-pvvc being exploited?
There is no known exploitation of GHSA-mhgm-52vg-pvvc in the wild and no public exploit code.