CVE-2026-12071 Overview
CVE-2026-12071 is an open redirect and HTTP response header injection vulnerability in the Webbox component of TeamDavid by Tobit Laboratories AG. The Webbox constructs redirect URLs by appending user-supplied input to the target in a 302 HTTP response. Attackers can inject URL-encoded characters such as %2e to manipulate the portion of the URL following the top-level domain (TLD), redirecting users to an attacker-controlled lookalike domain. URL-encoded line feeds also allow arbitrary HTTP response header injection. The issue affects TeamDavid through Rollout 524 and is tracked as CWE-601: URL Redirection to Untrusted Site.
Critical Impact
Attackers can craft URLs that redirect authenticated users to malicious lookalike domains and inject arbitrary HTTP response headers, enabling phishing, credential theft, and response splitting attacks.
Affected Products
- TeamDavid by Tobit Laboratories AG (Webbox component)
- All TeamDavid versions through Rollout 524
- Deployments exposing the Webbox redirect endpoint to untrusted networks
Discovery Timeline
- 2026-08-07 - CVE-2026-12071 published to NVD
- 2026-08-10 - Last updated in NVD database
Technical Details for CVE-2026-12071
Vulnerability Analysis
The Webbox in TeamDavid builds redirect URLs by concatenating user-supplied input directly into the Location header of an HTTP 302 response. The application does not validate or canonicalize the destination host before issuing the redirect. This behavior enables two distinct attacks: an open redirect abusing TLD boundaries and HTTP response splitting via header injection.
By submitting URL-encoded characters such as %2e (dot), an attacker manipulates parsing of the domain. If the application expects the domain example.com and an adversary registers a similar TLD such as example.company, encoded input can shift where the browser interprets the TLD boundary. The victim is redirected to the attacker's domain while the initial URL appears to originate from the trusted host.
The second attack vector uses URL-encoded line feeds (%0d%0a) in the redirect parameter. Because the input is placed into an HTTP response header without stripping CRLF sequences, an attacker can terminate the Location header and inject additional headers or response bodies. This enables cache poisoning, cookie fixation, and cross-site scripting through crafted responses.
Root Cause
The root cause is missing validation of user-controlled input used in redirect target construction. The Webbox trusts the redirect parameter and neither decodes-and-validates the URL structure nor filters CRLF characters before writing the Location header.
Attack Vector
Exploitation is remote and requires user interaction. An attacker delivers a crafted Webbox URL through phishing email, chat message, or a malicious link on a trusted-looking page. When the victim clicks the link, the Webbox returns a 302 response redirecting to the attacker-controlled domain, or the manipulated response contains injected headers processed by the victim's browser.
The vulnerability manifests in the redirect handler of the Webbox HTTP interface. Technical details are documented in the Infoguard CVE Analysis.
Detection Methods for CVE-2026-12071
Indicators of Compromise
- HTTP requests to the Webbox containing URL-encoded dots (%2e) or CRLF sequences (%0d%0a, %0a) in redirect parameters.
- Outbound 302 responses with Location headers pointing to domains that share a prefix with the legitimate host but end in a different TLD.
- Web server access logs showing redirect endpoints called with unusually long or encoded query strings from external referrers.
Detection Strategies
- Deploy web application firewall (WAF) rules that block CRLF characters and multiple encoded dots in redirect parameters.
- Correlate proxy and endpoint telemetry to identify users following Webbox 302 responses to newly registered or low-reputation domains.
- Inspect HTTP responses from the Webbox for multiple Location headers or headers appearing after Location that were not part of the application's normal response set.
Monitoring Recommendations
- Enable verbose access logging on the TeamDavid Webbox and forward logs to a SIEM for pattern matching on encoded redirect payloads.
- Monitor DNS resolution for domains resembling internal or partner brands under alternate TLDs (.company, .co, .net).
- Alert on user-agent redirects from the Webbox to external hosts outside an approved allowlist.
How to Mitigate CVE-2026-12071
Immediate Actions Required
- Upgrade TeamDavid to a Rollout newer than 524 as published in the David Tobit Release Notes.
- Restrict external access to the Webbox redirect endpoints until the patched Rollout is deployed.
- Register or defensively monitor lookalike TLD variants of your primary Webbox domain.
Patch Information
Tobit Laboratories AG addresses this issue in Rollouts released after Rollout 524. Administrators should review the David Tobit Release Notes for the specific fixed version and apply the update per vendor guidance. Confirm that redirect parameter validation and CRLF filtering are documented in the applied release.
Workarounds
- Deploy a reverse-proxy or WAF rule that rejects requests to Webbox redirect endpoints when the redirect parameter contains %0d, %0a, or repeated %2e sequences.
- Enforce a strict allowlist of permitted redirect destinations at the proxy layer, dropping any 302 response whose Location host is not on the list.
- Educate users about phishing links that reference the legitimate TeamDavid host but include long encoded query strings.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
