According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Binary / Bytecode Quality Analysis ``` Cost effective for partial coverage: ``` Bytecode Weakness Analysis - including disassembler + source code weakness analysis
CWE-477 Base Rascunho
Use of Obsolete Function
This vulnerability occurs when code relies on deprecated or obsolete functions, indicating outdated practices and insufficient maintenance that can introduce security gaps.
Definição
What is CWE-477?
This vulnerability occurs when code relies on deprecated or obsolete functions, indicating outdated practices and insufficient maintenance that can introduce security gaps.
Programming languages evolve, and functions become obsolete for several key reasons: language advancements, better understanding of secure and efficient operations, and shifting conventions. These deprecated functions are typically replaced by newer, more secure alternatives designed to perform the same tasks more effectively.
Using obsolete functions is a clear signal that code hasn't been actively reviewed or updated. This neglect can expose applications to unnecessary risks, as newer functions often address known security flaws, performance issues, or compatibility problems present in their older counterparts.
Impacto no mundo real
Real-world CVEs caused by CWE-477
Ainda não há referências CVE públicas associadas a este CWE no catálogo da MITRE.
Como os atacantes a exploram
Trajeto do atacante passo a passo
- 1
The following code uses the deprecated function getpw() to verify that a plaintext password matches a user's encrypted password. If the password is valid, the function sets result to 1; otherwise it is set to 0.
- 2
Although the code often behaves correctly, using the getpw() function can be problematic from a security standpoint, because it can overflow the buffer passed to its second parameter. Because of this vulnerability, getpw() has been supplanted by getpwuid(), which performs the same lookup as getpw() but returns a pointer to a statically-allocated structure to mitigate the risk. Not all functions are deprecated or replaced because they pose a security risk. However, the presence of an obsolete function often indicates that the surrounding code has been neglected and may be in a state of disrepair. Software security has not been a priority, or even a consideration, for very long. If the program uses deprecated or obsolete functions, it raises the probability that there are security problems lurking nearby.
- 3
In the following code, the programmer assumes that the system always has a property named "cmd" defined. If an attacker can control the program's environment so that "cmd" is not defined, the program throws a null pointer exception when it attempts to call the "Trim()" method.
- 4
The following code constructs a string object from an array of bytes and a value that specifies the top 8 bits of each 16-bit Unicode character.
- 5
In this example, the constructor may not correctly convert bytes to characters depending upon which charset is used to encode the string represented by nameBytes. Due to the evolution of the charsets used to encode strings, this constructor was deprecated and replaced by a constructor that accepts as one of its parameters the name of the charset used to encode the bytes for conversion.
Exemplo de código vulnerável
Vulnerable C
The following code uses the deprecated function getpw() to verify that a plaintext password matches a user's encrypted password. If the password is valid, the function sets result to 1; otherwise it is set to 0.
...
getpw(uid, pwdline);
for (i=0; i<3; i++){
cryptpw=strtok(pwdline, ":");
pwdline=0;
}
result = strcmp(crypt(plainpw,cryptpw), cryptpw) == 0;
... Exemplo de código seguro
Secure 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.
Lista de verificação de prevenção
How to prevent CWE-477
- Implementation Refer to the documentation for the obsolete function in order to determine why it is deprecated or obsolete and to learn about alternative ways to achieve the same functionality.
- Requirements Consider seriously the security implications of using an obsolete function. Consider using alternate functions.
Sinais de deteção
How to detect CWE-477
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Cost effective for partial coverage: ``` Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Debugger
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Manual Source Code Review (not inspections) ``` Cost effective for partial coverage: ``` Focused Manual Spotcheck - Focused manual analysis of source
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Source Code Quality Analyzer Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer
According to SOAR [REF-1479], the following detection techniques may be useful: ``` Highly cost effective: ``` Origin Analysis
O Plexicus deteta automaticamente o CWE-477 e abre um PR de correção em menos de 60 segundos.
O Codex Remedium analisa cada commit, identifica esta fraqueza exata e entrega um pull request pronto para revisão com o patch. Sem tickets. Sem transferências.
Perguntas frequentes O que é o CWE-477?
Qual a gravidade do CWE-477?
Que linguagens ou plataformas são afetadas pelo CWE-477?
Como posso prevenir o CWE-477?
Como é que o Plexicus deteta e corrige o CWE-477?
Onde posso saber mais sobre o CWE-477?
Frequently asked questions
O que é o CWE-477?
This vulnerability occurs when code relies on deprecated or obsolete functions, indicating outdated practices and insufficient maintenance that can introduce security gaps.
Qual a gravidade do CWE-477?
A MITRE não publicou uma classificação de probabilidade de exploração para esta fraqueza. Trate-a como impacto médio até o seu modelo de ameaças provar o contrário.
Que linguagens ou plataformas são afetadas pelo CWE-477?
A MITRE não especificou as plataformas afetadas por este CWE — pode aplicar-se à maioria das stacks de aplicações.
Como posso prevenir o CWE-477?
Refer to the documentation for the obsolete function in order to determine why it is deprecated or obsolete and to learn about alternative ways to achieve the same functionality. Consider seriously the security implications of using an obsolete function. Consider using alternate functions.
Como é que o Plexicus deteta e corrige o CWE-477?
O motor SAST do Plexicus correlaciona a assinatura de fluxo de dados do CWE-477 em cada commit. Quando é encontrada uma correspondência, o nosso agente Codex Remedium abre um PR de correção com o código corrigido, testes e um resumo de uma linha para o revisor.
Onde posso saber mais sobre o CWE-477?
A MITRE publica a definição canónica em https://cwe.mitre.org/data/definitions/477.html. Pode também consultar a documentação da OWASP e do NIST para orientações adjacentes.
Fraquezas relacionadas
Weaknesses related to CWE-477
CWE-710 Pai
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 Irmão
Use of Redundant Code
This weakness occurs when a codebase contains identical or nearly identical logic duplicated across multiple functions, methods, or…
CWE-1044 Irmão
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 Irmão
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 Irmão
Insufficient Technical Documentation
This weakness occurs when a software or hardware product lacks comprehensive technical documentation. Missing or incomplete details about…
CWE-1061 Irmão
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 Irmão
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 Irmão
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 Irmão
Inconsistency Between Implementation and Documented Design
This weakness occurs when the actual code implementation deviates from the intended design described in its official documentation,…
Recursos
Further reading
- MITRE — CWE-477 oficial https://cwe.mitre.org/data/definitions/477.html
- Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf
- State-of-the-Art Resources (SOAR) for Software Vulnerability Detection, Test, and Evaluation https://www.ida.org/-/media/feature/publications/s/st/stateoftheart-resources-soar-for-software-vulnerability-detection-test-and-evaluation/p-5061.ashx
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