CWE-1177 Class Incomplete

Use of Prohibited Code

This vulnerability occurs when software incorporates a function, library, or third-party component that has been explicitly banned by the development team or the customer.

Definition

What is CWE-1177?

This vulnerability occurs when software incorporates a function, library, or third-party component that has been explicitly banned by the development team or the customer.
Development teams or clients often create lists of prohibited code for critical reasons. These bans can stem from known security flaws, components that are notoriously hard to use safely, licensing conflicts, export control restrictions, reliance on obsolete or unmaintained code, or internal plans to phase out certain technologies. Ignoring these prohibitions directly introduces the specific risks the ban was meant to prevent. Using banned functions or libraries increases security risk and maintenance costs. These components often have inherent weaknesses that can lead to exploits, and they may force developers to write complex, error-prone workarounds. Furthermore, they can create technical debt through compatibility issues, legal problems from license violations, and increased support overhead for code that the team has officially decided not to support.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-1177

  • CVE-2007-1470

    Library has multiple buffer overflows using sprintf() and strcpy()

  • CVE-2007-4004

    FTP client uses inherently insecure gets() function and is setuid root on some systems, allowing buffer overflow

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    The code below calls the gets() function to read in data from the command line.

  2. 2

    However, gets() is inherently unsafe, because it copies all input from STDIN to the buffer without checking size. This allows the user to provide a string that is larger than the buffer size, resulting in an overflow condition.

  3. 3

    The following code attempts to create a local copy of a buffer to perform some manipulations to the data.

  4. 4

    However, the programmer does not ensure that the size of the data pointed to by string will fit in the local buffer and copies the data with the potentially dangerous strcpy() function. This may result in a buffer overflow condition if an attacker can influence the contents of the string parameter.

Verwundbares Codebeispiel

Vulnerable C

The code below calls the gets() function to read in data from the command line.

Verwundbar C 
char buf[24];
  	printf("Please enter your name and press <Enter>\n");
  	gets(buf);
  	...
  }
Sicheres Codebeispiel

Secure pseudo

Sicher pseudo 
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Präventions-Checkliste

How to prevent CWE-1177

  • Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
  • Implementation Validate input at trust boundaries; use allowlists, not denylists.
  • Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
  • Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
  • Operation Monitor logs for the runtime signals listed in the next section.
Erkennungssignale

How to detect CWE-1177

SAST High

Führe statische Analyse (SAST) auf der Codebasis aus und suche im Datenfluss nach dem unsicheren Muster.

DAST Moderate

Führe dynamische Application-Security-Tests gegen den Live-Endpoint aus.

Runtime Moderate

Beobachte Runtime-Logs auf ungewöhnliche Exception-Traces, fehlerhafte Eingaben oder Versuche, Autorisierung zu umgehen.

Code review Moderate

Code Review: Markiere jeden neuen Code, der Eingaben von dieser Oberfläche ohne validierte Framework-Helper verarbeitet.

Plexicus Auto-Fix

Plexicus erkennt CWE-1177 automatisch und öffnet in unter 60 Sekunden einen Fix-PR.

Codex Remedium scannt jeden Commit, identifiziert genau diese Schwachstelle und liefert einen reviewer-ready Pull Request mit dem Patch. Keine Tickets. Keine Hand-offs.

Demo anfordern Plexicus kostenlos testen
Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-1177?

This vulnerability occurs when software incorporates a function, library, or third-party component that has been explicitly banned by the development team or the customer.

Wie gravierend ist CWE-1177?

MITRE hat für diese Schwachstelle keine Exploit-Wahrscheinlichkeit veröffentlicht. Behandle sie als mittlere Auswirkung, bis dein Threat Model anderes belegt.

Welche Sprachen oder Plattformen sind von CWE-1177 betroffen?

MITRE hat für diese CWE keine betroffenen Plattformen spezifiziert — sie kann in den meisten Anwendungs-Stacks auftreten.

Wie kann ich CWE-1177 verhindern?

Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.

Wie erkennt und behebt Plexicus CWE-1177?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-1177 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.

Wo erfahre ich mehr über CWE-1177?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/1177.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-1177

CWE-710 Parent

Improper Adherence to Coding Standards

This weakness occurs when developers don't consistently follow established coding standards and best practices, which can introduce…

CWE-1041 Sibling

Use of Redundant Code

This weakness occurs when a codebase contains identical or nearly identical logic duplicated across multiple functions, methods, or…

CWE-1044 Sibling

Architecture with Number of Horizontal Layers Outside of Expected Range

This occurs when a software system is built with either too many or too few distinct architectural layers, falling outside a recommended…

CWE-1048 Sibling

Invokable Control Element with Large Number of Outward Calls

This weakness occurs when a single function, method, or callable code block makes an excessively high number of calls to other objects or…

CWE-1059 Sibling

Insufficient Technical Documentation

This weakness occurs when a software or hardware product lacks comprehensive technical documentation. Missing or incomplete details about…

CWE-1061 Sibling

Insufficient Encapsulation

This weakness occurs when a software component exposes too much of its internal workings, such as data structures or implementation logic.…

CWE-1065 Sibling

Runtime Resource Management Control Element in a Component Built to Run on Application Servers

This weakness occurs when an application built to run on a managed application server bypasses the server's high-level APIs and instead…

CWE-1066 Sibling

Missing Serialization Control Element

This weakness occurs when a class or data structure is marked as serializable but lacks the required control methods to properly handle…

CWE-1068 Sibling

Inconsistency Between Implementation and Documented Design

This weakness occurs when the actual code implementation deviates from the intended design described in its official documentation,…

Ressourcen

Further reading

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