Security Resilience

CVE-2023-26451

Crypto Weakness in Open-Xchange Appsuite Backend ≤ 8.11.0

Public PoCCrypto Weakness
Published
02 August 2023
Modified
21 November 2024
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.012 67th percentile
Risk Priority 60 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-26451 is a high-severity Use of Insufficiently Random Values (CWE-330) vulnerability in Open-Xchange Open-Xchange Appsuite Backend. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 33% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Functions with insufficient randomness were used to generate authorization tokens of the integrated oAuth Authorization Service. Authorization codes were predictable for third parties and could be used to intercept and take over the client authorization process. As a result, other…

more

users accounts could be compromised. The oAuth Authorization Service is not enabled by default. We have updated the implementation to use sources with sufficient randomness to generate authorization tokens. No publicly available exploits are known.

CWE(s)

Related Threats

CVEs Like This One

CVE-2023-26435Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26434Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26429Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26431Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26433Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26438Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26428Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26436Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26432Same product: Open-Xchange Open-Xchange Appsuite Backend
CVE-2023-26430Same product: Open-Xchange Open-Xchange Appsuite Backend

Affected Assets

open-xchange
open-xchange appsuite backend
≤ 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-330

Key generation under controlled management uses approved random-bit sources rather than insufficiently random values.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

blocks

Cryptographic controls require use of approved, sufficiently random values for keys and nonces.

blocks

Secure SDLC processes include verification steps that can catch insufficient randomness but do not directly specify RNG requirements.

prevents

Secure coding standards explicitly prohibit use of weak or predictable random number generators.

finds

Security testing can detect weak randomness but does not prescribe the control itself.

degrades

Secure authentication mechanisms depend on unpredictable values (nonces, salts, session tokens) to resist guessing.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

References