6.9
MEDIUM CVSS 4.0
CVE-2025-27090
Sliver Teamserver Unauthenticated Reverse Port Forwarding Vulnerability
Description

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 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.

INFO

Published Date :

Feb. 19, 2025, 10:15 p.m.

Last Modified :

Feb. 27, 2025, 8:18 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2025-27090 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Bishopfox sliver
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM [email protected]
Solution
Upgrade Sliver teamserver to version 1.5.43 or later to fix reverse port forwarding.
  • Upgrade Sliver to version 1.5.43 or later.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-27090.

URL Resource
https://github.com/BishopFox/sliver/commit/0f340a25cf3d496ed870dae7da39eab4427bc16f Patch
https://github.com/BishopFox/sliver/commit/10e245326070c6a5884a02e0790bb7e2baefb3a1 Patch
https://github.com/BishopFox/sliver/security/advisories/GHSA-fh4v-v779-4g2w Exploit Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-27090 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-27090 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-27090 vulnerability anywhere in the article.

  • Cyber Security News
Sliver C2 Server Vulnerability Let Attackers Open a TCP connection to Read Traffic

A critical server-side request forgery (SSRF) vulnerability (CVE-2025-27090) has been identified in the Sliver C2 framework’s teamserver implementation, enabling attackers to establish unauthorized TC ... Read more

Published Date: Feb 25, 2025 (6 months ago)
  • Cyber Security News
Hackers Bypassing Outlook Spam Filter to Deliver Weaponized ISO Files

A newly uncovered technique allows threat actors to bypass Microsoft Outlook’s spam filtering mechanisms, enabling the delivery of malicious ISO files through seemingly benign email links. This vulner ... Read more

Published Date: Feb 25, 2025 (6 months ago)

The following table lists the changes that have been made to the CVE-2025-27090 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Feb. 27, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
    Added CPE Configuration OR *cpe:2.3:a:bishopfox:sliver:*:*:*:*:*:*:*:* versions from (including) 1.5.26 from (excluding) 1.5.43
    Added Reference Type GitHub, Inc.: https://github.com/BishopFox/sliver/commit/0f340a25cf3d496ed870dae7da39eab4427bc16f Types: Patch
    Added Reference Type GitHub, Inc.: https://github.com/BishopFox/sliver/commit/10e245326070c6a5884a02e0790bb7e2baefb3a1 Types: Patch
    Added Reference Type GitHub, Inc.: https://github.com/BishopFox/sliver/security/advisories/GHSA-fh4v-v779-4g2w Types: Exploit, Vendor Advisory
  • New CVE Received by [email protected]

    Feb. 19, 2025

    Action Type Old Value New Value
    Added Description 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 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.
    Added CVSS V4.0 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
    Added CWE CWE-918
    Added Reference https://github.com/BishopFox/sliver/commit/0f340a25cf3d496ed870dae7da39eab4427bc16f
    Added Reference https://github.com/BishopFox/sliver/commit/10e245326070c6a5884a02e0790bb7e2baefb3a1
    Added Reference https://github.com/BishopFox/sliver/security/advisories/GHSA-fh4v-v779-4g2w
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 6.9
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability
Base CVSS Score: 5.3
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact