SSRF in Open-Xchange Appsuite Backend
CVE-2023-26438
External service lookups for a number of protocols were vulnerable to a time-of-check/time-of-use (TOCTOU) weakness, involving the JDK DNS cache. Attackers that were timing DNS cache expiry correctly were able to inject configuration that would bypass existing network deny-lists. Attackers could exploit this weakness to discover the existence of restricted network infrastructure and service availability. Improvements were made to include deny-lists not only during the check of the provided connection data, but also during use. No publicly available exploits are known.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (46.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Open-Xchange Appsuite Backend — versions 7.10.6, 8.10.0
- Ox Software Gmbh App Suite — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- software.open-xchange.com/products/appsuite/doc/Release_Notes_for_Patch_Release… (release-notes, Release Notes)
- documentation.open-xchange.com/appsuite/security/advisories/csaf/2023/oxas-adv-… (vendor-advisory)
- seclists.org/fulldisclosure/2023/Aug/8 (Mailing List, Third Party Advisory)
- packetstormsecurity.com/files/173943/OX-App-Suite-SSRF-SQL-Injection-Cross-Site… (VDB Entry, Third Party Advisory)
Frequently asked questions
- What is CVE-2023-26438?
- CVE-2023-26438 is a medium-severity vulnerability in Open-Xchange Appsuite Backend, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.3/10. Published 2023-08-02.
- How severe is CVE-2023-26438?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2023-26438 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.