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GHSA-28f5-38xr-jh2w

HighCVSS 8.2 / 10
Published Jul 28, 2026·Last modified Jul 28, 2026
Affected Components(0)

No affected components available

Description

Summary

When directConnect(true) is enabled, appium/java-client unconditionally accepts directConnectHost, directConnectPort, and directConnectPath from the server's NEW_SESSION response and silently redirects all subsequent session traffic to the attacker-specified endpoint — with no allowlist, no host validation, and no user notification.

Affected Code

  • AppiumCommandExecutor.java (line 196–219): setDirectConnect() builds a new URL from server-supplied fields and calls overrideServerUrl(newUrl) without validating host/IP.
  • DirectConnect.java: getUrl() constructs protocol://host:port/path with no allowlist.

Root Cause

Only the protocol is validated (must equal "https"). The destination host and port are never checked against any allowlist or denylist.

PoC (confirmed)

A rogue server injecting directConnectHost=127.0.0.1:4443 causes the client to silently redirect all post-session commands:

[bootstrap] POST /wd/hub/session [bootstrap] Injecting directConnect -> https://127.0.0.1:4443/wd/hub [redirect-target] HIT #1: GET /wd/hub/session/poc-session-001/source [redirect-target] HIT #2: DELETE /wd/hub/session/poc-session-001

Original source code unmodified — confirmed via git diff HEAD (empty).

Evidence Screenshots

Screenshot 1 — Rogue server capturing redirected traffic:

<img width="887" height="146" alt="1" src="https://github.com/user-attachments/assets/cc28002c-ea20-4ac8-8336-cec632e3c842" />

Screenshot 2 — Java client processing response from attacker host:

<img width="788" height="130" alt="2" src="https://github.com/user-attachments/assets/222cbab0-0d53-45b2-847d-6aa4e3b79370" />

Impact

  • Full interception of session traffic
  • Network pivot to internal hosts (RFC-1918, 169.254.169.254)
  • Cloud credential theft via IMDS endpoint
  • Escalates to ~8.1 High in CI/CD environments where directConnect(true) is set in shared base configuration

Suggested Fix

Add allowlist validation before overrideServerUrl() is called, and/or block RFC-1918/loopback/link-local destinations by default.

poc_appium_directconnect.zip

Risk Scores
Base Score
8.2

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information. There is a low impact on the integrity of the data.

Threat Intelligence
7.5

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.24%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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