界: Code Quality

程式碼品質不佳，會導致無法預料的行為。從使用者的角度來看，這通常表現為可用性不佳。對於攻擊者而言，這提供了以意想不到的方式向系統施加壓力的機會。

Memory Leak

Abstract

記憶體被分配後將永遠不會被釋放。

Explanation

記憶體洩露有兩個常見的原因 (有時這兩個原因會一起出現)：

- 錯誤條件以及其他異常情況。

- 對於程式中負責釋放記憶體的部分混淆了。

大部分記憶體洩漏會導致一般軟體可靠性問題，但是如果攻擊者能夠蓄意觸發資源的洩漏，攻擊者就可能會發動 Denial of Service 攻擊 (藉由損壞程式)，或利用因記憶體不足的狀況 [1] 導致的其他非預期程式行為。

範例 1：以下 C 函數將會洩漏已分配的記憶體區塊的資訊，當程式呼叫 read() 時未能回傳預期的位元組數：


  char* getBlock(int fd) {
  char* buf = (char*) malloc(BLOCK_SIZE);
  if (!buf) {
    return NULL;
  }
  if (read(fd, buf, BLOCK_SIZE) != BLOCK_SIZE) {
    return NULL;
  }
  return buf;
}

References

[1] J. Whittaker and H. Thompson How to Break Software Security Addison Wesley

[2] Standards Mapping - Common Weakness Enumeration CWE ID 401

[3] Standards Mapping - DISA Control Correlation Identifier Version 2 CCI-001094

[4] Standards Mapping - General Data Protection Regulation (GDPR) Indirect Access to Sensitive Data

[5] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2012 Rule 21.3

[6] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C Guidelines 2023 Rule 21.3

[7] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C++ Guidelines 2008 Rule 18-4-1

[8] Standards Mapping - Motor Industry Software Reliability Association (MISRA) C++ Guidelines 2023 Rule 21.6.1

[9] Standards Mapping - NIST Special Publication 800-53 Revision 4 SC-5 Denial of Service Protection (P1)

[10] Standards Mapping - NIST Special Publication 800-53 Revision 5 SC-5 Denial of Service Protection

[11] Standards Mapping - OWASP Mobile Application Security Verification Standard 2.0 MASVS-STORAGE-2

[12] Standards Mapping - OWASP Top 10 2004 A9 Application Denial of Service

[13] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 Requirement 6.5.9

[14] Standards Mapping - Payment Card Industry Data Security Standard Version 3.0 Requirement 6.5.6

[15] Standards Mapping - Payment Card Industry Data Security Standard Version 3.1 Requirement 6.5.6

[16] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2 Requirement 6.5.6

[17] Standards Mapping - Payment Card Industry Data Security Standard Version 3.2.1 Requirement 6.5.6

[18] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0 Requirement 6.2.4

[19] Standards Mapping - Payment Card Industry Data Security Standard Version 4.0.1 Requirement 6.2.4

[20] Standards Mapping - Payment Card Industry Software Security Framework 1.0 Control Objective 4.2 - Critical Asset Protection

[21] Standards Mapping - Payment Card Industry Software Security Framework 1.1 Control Objective 4.2 - Critical Asset Protection

[22] Standards Mapping - Payment Card Industry Software Security Framework 1.2 Control Objective 4.2 - Critical Asset Protection

[23] Standards Mapping - Security Technical Implementation Guide Version 3.1 APP6080 CAT II

[24] Standards Mapping - Security Technical Implementation Guide Version 3.4 APP6080 CAT II

[25] Standards Mapping - Security Technical Implementation Guide Version 3.5 APP6080 CAT II

[26] Standards Mapping - Security Technical Implementation Guide Version 3.6 APP6080 CAT II

[27] Standards Mapping - Security Technical Implementation Guide Version 3.7 APP6080 CAT II

[28] Standards Mapping - Security Technical Implementation Guide Version 3.9 APP6080 CAT II

[29] Standards Mapping - Security Technical Implementation Guide Version 3.10 APP6080 CAT II

[30] Standards Mapping - Security Technical Implementation Guide Version 4.2 APSC-DV-002400 CAT II

[31] Standards Mapping - Security Technical Implementation Guide Version 4.3 APSC-DV-002400 CAT II

[32] Standards Mapping - Security Technical Implementation Guide Version 4.4 APSC-DV-002400 CAT II

[33] Standards Mapping - Security Technical Implementation Guide Version 4.5 APSC-DV-002400 CAT II

[34] Standards Mapping - Security Technical Implementation Guide Version 4.6 APSC-DV-002400 CAT II

[35] Standards Mapping - Security Technical Implementation Guide Version 4.7 APSC-DV-002400 CAT II

[36] Standards Mapping - Security Technical Implementation Guide Version 4.8 APSC-DV-002400 CAT II

[37] Standards Mapping - Security Technical Implementation Guide Version 4.9 APSC-DV-002400 CAT II

[38] Standards Mapping - Security Technical Implementation Guide Version 4.10 APSC-DV-002400 CAT II

[39] Standards Mapping - Security Technical Implementation Guide Version 4.11 APSC-DV-002400 CAT II

[40] Standards Mapping - Security Technical Implementation Guide Version 4.1 APSC-DV-002400 CAT II

[41] Standards Mapping - Security Technical Implementation Guide Version 5.1 APSC-DV-002400 CAT II

[42] Standards Mapping - Security Technical Implementation Guide Version 5.2 APSC-DV-002400 CAT II

[43] Standards Mapping - Security Technical Implementation Guide Version 5.3 APSC-DV-002400 CAT II

[44] Standards Mapping - Security Technical Implementation Guide Version 6.1 APSC-DV-002400 CAT II

[45] Standards Mapping - Web Application Security Consortium Version 2.00 Denial of Service (WASC-10)

[46] Standards Mapping - Web Application Security Consortium 24 + 2 Denial of Service

desc.controlflow.cpp.memory_leak

Abstract

記憶體已配置但從未釋放。

Explanation

記憶體洩漏有兩個常見且有時重疊的原因：

- 錯誤條件以及其他異常情況。

- 不確定程式的哪一部分負責釋放記憶體。

大多數的記憶體洩漏會導致一般的軟體可靠性問題，但是如果攻擊者蓄意觸發記憶體洩漏，則攻擊者可能可以發動 Denial of Service 攻擊 (透過使程式當機的方式)，或利用由記憶不足狀況導致的其他意外程式行為[1]。

範例 1：如果發生錯誤，以下 Micro Focus COBOL 程式將會洩漏配置的記憶體區塊：


  CALL "CBL_ALLOC_MEM"
      USING mem-pointer
      BY VALUE mem-size
      BY VALUE flags
      RETURNING status-code
  END-CALL

  IF status-code NOT = 0
      DISPLAY "Error!"
      GOBACK
  ELSE
      SET ADDRESS OF mem TO mem-pointer
  END-IF

  PERFORM write-data
  IF ws-status-code NOT = 0
      DISPLAY "Error!"
      GOBACK
  ELSE
      DISPLAY "Success!"
  END-IF

  CALL "CBL_FREE_MEM"
      USING BY VALUE mem-pointer
      RETURNING status-code
  END-CALL

  GOBACK
  .