# CVE-2025-27090: Server-Side Request Forgery (SSRF) in sliver teamserver

> An attacker can expose the server's IP address via unverified reverse port forwarding in the Sliver teamserver, requiring an upgrade to mitigate.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Feb 2025
- **Updated:** 19 Feb 2025
- **Also known as:** GHSA-fh4v-v779-4g2w, GO-2025-3472

## What is CVE-2025-27090?

CVE-2025-27090 is a medium-severity server-side request forgery vulnerability in BishopFox sliver, published on 19 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2025-27090?

3 open source packages ship an affected version, including github.com/bishopfox/sliver. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/bishopfox/sliver` | Go | From 1.5.26 | 1.5.43 |
| `github.com/bishopfox/sliver` | Go | From 1.5.26 | 1.5.43 |
| `github.com/bishopfox/sliver` | Go | From 1.5.26 | 1.5.43 |

Products: Bishopfox Sliver.

## How do I fix CVE-2025-27090?

Upgrade github.com/bishopfox/sliver to 1.5.43 or later.

## Is CVE-2025-27090 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-27090 exists.

## Other vulnerabilities in BishopFox sliver

- [CVE-2023-34758](https://insights.sbomify.com/CVE-2023-34758/): Silver vulnerable to MitM attack against implants due to a cryptography vulnerability (high 8.1)
- [CVE-2026-25791](https://insights.sbomify.com/CVE-2026-25791/): Sliver has a DNS C2 OTP Bypass Allows Unauthenticated Session Flooding and Denial of Service (high 7.5)
- [CVE-2026-25760](https://insights.sbomify.com/CVE-2026-25760/): Website Path Traversal / Arbitrary File Read (Authenticated) in Sliver (medium 6.5)
- [CVE-2026-34227](https://insights.sbomify.com/CVE-2026-34227/): Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface (medium 5.9)
- [CVE-2026-32941](https://insights.sbomify.com/CVE-2026-32941/): Sliver Vulnerable to Authenticated OOM via Memory Exhaustion in mTLS/WireGuard Transports (medium 5.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-27090 and fix it if it is affected.

What it is: CVE-2025-27090 is a medium-severity server-side request forgery vulnerability in BishopFox sliver, published on 19 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-27090 exists.

Affected packages and fixed versions:
- github.com/bishopfox/sliver (Go): affected from 1.5.26; fixed in 1.5.43
- github.com/bishopfox/sliver (Go): affected from 1.5.26; fixed in 1.5.43
- github.com/bishopfox/sliver (Go): affected from 1.5.26; fixed in 1.5.43

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-27090/ (Markdown: https://insights.sbomify.com/CVE-2025-27090/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-27090
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-27090
- OSV: https://osv.dev/vulnerability/CVE-2025-27090

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-27090/
Summaries are generated and may contain mistakes; the official description above is the record.