Cyber Resilience

CVE-2023-34758

Crypto Weakness in Bishopfox Sliver 1.5.0 – 1.5.40

Published
28 August 2023
Modified
21 November 2024
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0059 45th percentile
Risk Priority 60 floored blend · peak EPSS

Summary

CVE-2023-34758 is a high-severity Use of a Broken or Risky Cryptographic Algorithm (CWE-327) vulnerability in Bishopfox Sliver. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 45th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Sliver from v1.5.x to v1.5.39 has an improper cryptographic implementation, which allows attackers to execute a man-in-the-middle attack via intercepted and crafted responses.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-34227Same product: Bishopfox Sliver
CVE-2026-32941Same product: Bishopfox Sliver
CVE-2025-27090Same product: Bishopfox Sliver
CVE-2026-29781Same product: Bishopfox Sliver
CVE-2026-25791Same product: Bishopfox Sliver
CVE-2026-25760Same product: Bishopfox Sliver
CVE-2023-40696Shared CWE-327
CVE-2024-4765Shared CWE-327
CVE-2026-6412Shared CWE-327
CVE-2023-23040Shared CWE-327

Affected Assets

bishopfox
sliver
1.5.0 — 1.5.40

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)

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-327

Contacts with security groups provide timely information on broken or risky cryptographic algorithms, reducing the likelihood of their selection and use.

addresses: CWE-327

Ongoing education and sharing of recommended practices helps organizations identify and migrate away from broken or risky cryptographic algorithms.

addresses: CWE-327

Cross-organization threat feeds commonly include advances in cryptanalysis and active exploits against weak or broken algorithms, allowing organizations to deprecate them proactively.

addresses: CWE-327

Capital planning and funding allow selection and ongoing support of strong cryptographic algorithms rather than weak or broken ones.

addresses: CWE-327

Risk updates surface newly-broken or risky cryptographic algorithms as threat intelligence and computing advances evolve, enabling timely replacement.

addresses: CWE-327

Scanners flag use of broken or weak cryptographic algorithms via known-vulnerability databases.

addresses: CWE-327

Enforces approved cryptographic algorithms for each use case, blocking use of broken or risky algorithms.

addresses: CWE-327

Flaw remediation replaces broken or risky cryptographic algorithms once safer implementations are released by vendors.

Mitigating Controls (NIST CSF 2.0) AI

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

PR.DS-01 partial match
prevents

PR.DS-01 promotes encryption for data-at-rest but never requires strong algorithms, leaving CWE-327 fully possible; the weakness is also far broader than data-at-rest so one narrow control removes none of its total risk.

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.

prevents

Mandating approved algorithms, cipher strength and usage standards directly stops the selection of broken or weak cryptographic primitives that attackers can exploit.

prevents

The explicit call-out of cryptography-related legal constraints (import/export, key escrow, digital-signature validity) reduces the likelihood that an organization will adopt broken or non-compliant cryptographic algorithms that violate those rules.

prevents

Access to current specialist guidance and early vulnerability alerts enables timely replacement of broken or risky cryptographic algorithms with stronger alternatives.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-327
Windows 10 (1 rule)
  • V-220937 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows 11 (1 rule)
  • V-253461 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2016 (1 rule)
  • V-225053 Windows Server 2016 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2019 (1 rule)
  • V-205654 Windows Server 2019 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2022 (1 rule)
  • V-254474 Windows Server 2022 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327

References