CVE-2026-54214: TeamDavid Webbox HTTP Header Injection

CVE-2026-54214 Overview

CVE-2026-54214 is an HTTP header injection vulnerability in Tobit Laboratories AG TeamDavid's Webbox application. The flaw resides in the cType URL parameter, which does not properly restrict control characters. Attackers can inject URL-encoded newlines (%0a) and colons to modify the Content-Type header and append arbitrary headers, including additional Location headers. This creates an open redirect condition classified under [CWE-601]. The issue affects TeamDavid through Rollout 524. See the Infoguard CVE Analysis Blog for research context and the David Tobit Release Notes for fixed builds.

Critical Impact
Attackers can craft malicious URLs that redirect victims to attacker-controlled hosts, enabling phishing campaigns and response manipulation.

Affected Products

Tobit Laboratories AG TeamDavid (Webbox component)
TeamDavid releases up to and including Rollout 524
Deployments exposing the Webbox HTTP interface to untrusted networks

Discovery Timeline

2026-08-07 - CVE-2026-54214 published to NVD
2026-08-07 - Last updated in NVD database

Technical Details for CVE-2026-54214

Vulnerability Analysis

The Webbox HTTP handler reflects the value of the cType query parameter directly into the outbound Content-Type header. The handler fails to filter carriage return (%0d) and line feed (%0a) sequences before assembling the response. Attackers exploit this by appending encoded newline characters followed by additional header names and values. Because the injected content is parsed as part of the HTTP response header block, the client treats attacker-controlled headers as legitimate server output. Injecting a second Location header converts the response into an open redirect that steers browsers toward external domains.

Root Cause

The underlying weakness is improper neutralization of CRLF sequences and colons in a user-controlled parameter used for response header construction. The application trusts the cType value for header assembly without applying an allow-list of MIME types or stripping control characters. This maps to [CWE-601] (URL Redirection to Untrusted Site) as the exploitable consequence, with header injection as the root mechanism.

Attack Vector

Exploitation requires user interaction. An attacker crafts a URL to a TeamDavid Webbox endpoint that includes a manipulated cType parameter containing URL-encoded newlines and a forged Location header. When a victim clicks the link, the Webbox server returns an HTTP response containing the injected headers. The victim's browser follows the attacker-controlled redirect target, enabling credential phishing or delivery of malicious payloads under the trust context of the legitimate Webbox host. The vulnerability manifests through the cType URL parameter; see the Infoguard CVE Analysis Blog for technical details.

Detection Methods for CVE-2026-54214

Indicators of Compromise

HTTP request logs containing %0a, %0d, or literal newlines within the cType query parameter targeting Webbox endpoints.
Server responses containing multiple Location headers or unexpected Content-Type values originating from Webbox.
Referrer chains showing users redirected from a TeamDavid Webbox URL to an external, unrelated domain.

Detection Strategies

Inspect web server and reverse proxy logs for requests where cType contains encoded control characters or a colon.
Deploy web application firewall rules that reject requests with CRLF sequences in query string parameters bound for Webbox routes.
Correlate outbound redirects from Webbox hostnames against a baseline of expected internal destinations.

Monitoring Recommendations

Alert on any HTTP 3xx response from Webbox that carries a Location header pointing to an external domain.
Track user click-through events from TeamDavid URLs to newly registered or low-reputation domains.
Retain full request and response headers for the Webbox service for at least 30 days to support incident review.

How to Mitigate CVE-2026-54214

Immediate Actions Required

Upgrade TeamDavid past Rollout 524 to a fixed build listed in the David Tobit Release Notes.
Restrict external exposure of the Webbox interface until the patched release is deployed.
Add WAF signatures that block URL parameters containing %0a, %0d, or unencoded newline bytes.

Patch Information

Tobit Laboratories has issued updated TeamDavid Rollouts addressing the header injection flaw. Administrators should consult the David Tobit Release Notes for the specific Rollout that resolves CVE-2026-54214 and apply it across all Webbox servers.

Workarounds

Enforce an allow-list of accepted Content-Type values at an upstream reverse proxy and drop requests that supply unexpected cType values.
Configure the proxy to strip or normalize CRLF sequences from all inbound query strings before forwarding to Webbox.
Deploy browser-side protections such as strict referrer policies and warn users about redirects originating from Webbox links.

bash

# Example NGINX rule to block CRLF injection in the cType parameter
if ($args ~* "cType=[^&]*(%0a|%0d|\r|\n|:)") {
    return 400;
}