CVE-2023-23943 Blind SSRF via server URL input in the Nextcloud Mail app
Attackers can exploit blind SSRF in Nextcloud Mail to scan internal network services via server URL inputs.
- 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-2023-23943?
CVE-2023-23943 is a medium-severity server-side request forgery vulnerability in nextcloud security-advisories, published on 6 Feb 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Nextcloud mail is an email app for the nextcloud home server platform. In affected versions the SMTP, IMAP and Sieve host fields allowed to scan for internal services and servers reachable from within the local network of the Nextcloud Server. It is recommended that the Nextcloud Maill app is upgraded to 1.15.0 or 2.2.2. The only known workaround for this issue is to completely disable the nextcloud mail app.
Weakness: CWE-918
Which versions are affected by CVE-2023-23943?
It affects 1 product.
Products include Nextcloud Mail.
How do I fix CVE-2023-23943?
No fix has been published for CVE-2023-23943 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2023-23943 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-23943 exists.
Other vulnerabilities in nextcloud security-advisories
- CVE-2021-32652 Missing permission check on email metadata retrieval
- CVE-2022-31132 Unauthenticated SSRF in 3rd party module "cerdic/csstidy"
- CVE-2024-52508 Nextcloud Mail auto configurator can be tricked into sending account information to wrong servers
- CVE-2023-45660 Require strict cookies for image proxy requests in Nextcloud Mail
- CVE-2021-32707 Bypass of image blocking in Nextcloud Mail
Sources
Also known as GHSA-8gcx-r739-9pf6.