Page History

...

// s.h
struct S {
  char c;
  int a;
};
 
void init_s(S &s);
 
// s.cpp
#include "s.h"
 
void init_s(S &s); {
  s.c = 'a';
  s.a = 12;
}
 
// a.cpp
#pragma pack(push, 1)
#include "s.h"
#pragma pack(pop)
 
void f() {
  S s;
  init_s(s);
}

...

// s.h
struct S {
  char c;
  int a;
};
 
void init_s(S &s);
 
// s.cpp
#include "s.h"
 
void init_s(S &s); {
  s.c = 'a';
  s.a = 12;
}
 
// a.cpp
#include "s.h"
 
void f() {
  S s;
  init_s(s);
}

...

Violating the ODR causes undefined behavior, which can result in exploits as well as denial-of-service attacks. As shown in "Support for Whole-Program Analysis and the Verification of the One-Definition Rule in C++" [Quinlan 06], failing to enforce the ODR enables a virtual function pointer attack known as the VPTR exploit. In this exploit, an object's virtual function table is corrupted so that calling a virtual function on the object results in malicious code being executed. See the paper by Quinlan and colleagues for more details. However, note that to introduce the malicious class, the attacker must have access to the system building the code.

Automated Detection

Related Vulnerabilities

Search for vulnerabilities resulting from the violation of this rule on the CERT website.

...