CVE-2023-26433 Denial of service in OX App Suite

Medium 4.3 Published 20 Jun 2023 Updated 2 Aug 2024

An attacker with a rogue IMAP service can cause denial of service in OX App Suite by sending oversized IMAP capability responses.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2023-26433?

CVE-2023-26433 is a medium-severity denial of service vulnerability in OX App Suite, published on 20 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

When adding an external mail account, processing of IMAP "capabilities" responses are not limited to plausible sizes. Attacker with access to a rogue IMAP service could trigger requests that lead to excessive resource usage and eventually service unavailability. We now limit accepted IMAP server response to reasonable length/size. No publicly available exploits are known.

Weakness: CWE-400

Which versions are affected by CVE-2023-26433?

It affects 1 product.

Products include Open-Xchange Open-Xchange Appsuite Backend.

How do I fix CVE-2023-26433?

No fix has been published for CVE-2023-26433 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-26433 being exploited?

There is no known exploitation of CVE-2023-26433 in the wild and no public exploit code.

Sources

Also known as GHSA-f8cc-v72f-5rm2.