Cyber Resilience

CVE-2023-26432

MediumPublic PoC

Published: 20 June 2023

Published
20 June 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0013 32.1th percentile
Risk Priority 9 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-26432 is a medium-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Open-Xchange Open-Xchange Appsuite Backend. Its CVSS base score is 4.3 (Medium).

Operationally, ranked at the 32.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

When adding an external mail account, processing of SMTP "capabilities" responses are not limited to plausible sizes. Attacker with access to a rogue SMTP service could trigger requests that lead to excessive resource usage and eventually service unavailability. We now…

more

limit accepted SMTP server response to reasonable length/size. No publicly available exploits are known.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

open-xchange
open-xchange appsuite backend
7.10.6 · ≤ 7.10.6 · 8.0.0 — 8.11.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-400

Limiting concurrent sessions directly prevents uncontrolled resource consumption by capping the number of active sessions per user or account.

addresses: CWE-400

Analysis identifies uncontrolled resource consumption indicative of denial-of-service or abuse attempts.

addresses: CWE-400

Contingency plan testing includes resource exhaustion scenarios to verify recovery, making it harder for attackers to sustain exploits that cause uncontrolled consumption.

addresses: CWE-400

Updated contingency plans include current procedures to detect, contain, and recover from resource exhaustion, limiting an attacker's ability to sustain impact from uncontrolled consumption.

addresses: CWE-400

Alternate site allows resumption of operations if resource exhaustion at the primary site is exploited to cause unavailability.

addresses: CWE-400

Alternate telecommunications services enable resumption of essential functions when primary services become unavailable due to uncontrolled resource consumption.

addresses: CWE-400

The team can analyze and respond to resource exhaustion incidents, reducing the impact of attacks that exploit uncontrolled consumption weaknesses.

addresses: CWE-400

Timely maintenance support and spare parts enable rapid recovery from failures induced by uncontrolled resource consumption, shortening the impact window of denial-of-service attacks.

References