Cyber Resilience

CVE-2025-27090

SSRF in Bishopfox Sliver 1.5.26 – 1.5.43

Public PoCSSRF
Published
19 February 2025
Modified
27 February 2025
Patch / advisory
View advisory
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0060 46th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2025-27090 is a medium-severity SSRF (CWE-918) vulnerability in Bishopfox Sliver. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 46th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability Data

Sliver is an open source cross-platform adversary emulation/red team framework, it can be used by organizations of all sizes to perform security testing. The reverse port forwarding in sliver teamserver allows the implant to open a reverse tunnel on the…

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sliver teamserver without verifying if the operator instructed the implant to do so. The only impact that has been shown is the exposure of the server's IP address to a third party. This issue has been addressed in version 1.5.43 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

CWE(s)
CWE-918

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-25760Same product: Bishopfox Sliver
CVE-2026-34227Same product: Bishopfox Sliver
CVE-2026-25791Same product: Bishopfox Sliver
CVE-2026-29781Same product: Bishopfox Sliver
CVE-2026-32941Same product: Bishopfox Sliver
CVE-2023-34758Same product: Bishopfox Sliver
CVE-2025-46568Shared CWE-918
CVE-2024-51408Shared CWE-918
CVE-2026-15525Shared CWE-918
CVE-2025-28089Shared CWE-918

Affected Assets

bishopfox
sliver
1.5.26 — 1.5.43

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Mitigating Controls (NIST 800-53 r5) AI

AC-4 Information Flow Enforcement good match

Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.

SI-10 Information Input Validation good match

Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.

SC-7 Boundary Protection partial match

Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.

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.PS-06 mostly match
prevents

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

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.

A.5.7 Threat intelligence partial match
prevents

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References