alpine 3.8
misc weakness #38


Weakness Breakdown


The software specifies permissions for a security-critical resource in a way that allows the resource to be read or modified by unintended actors.

Warning code(s):

Never create NULL ACLs; an attacker can set it to Everyone.

File Name:



The highlighted line of code below is the trigger point of this particular Alpine 3.8 misc weakness.

     ssize_t nbytes = ::recv (r, &dummy, sizeof (dummy), 0);
    errno_assert (nbytes >= 0);
    zmq_assert (nbytes == sizeof (dummy));
    zmq_assert (dummy == 0);

int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
#if defined ZMQ_HAVE_EVENTFD

    // Create eventfd object.
    fd_t fd = eventfd (0, 0);
    errno_assert (fd != -1);
    *w_ = fd;
    *r_ = fd;
    return 0;

#elif defined ZMQ_HAVE_WINDOWS

    InitializeSecurityDescriptor(&sd, SECURITY_DESCRIPTOR_REVISION);
    SetSecurityDescriptorDacl(&sd, TRUE, 0, FALSE);

    sa.nLength = sizeof(SECURITY_ATTRIBUTES);
    sa.lpSecurityDescriptor = &sd;

    //  This function has to be in a system-wide critical section so that
    //  two instances of the library don't accidentally create signaler
    //  crossing the process boundary.
    //  We'll use named event object to implement the critical section.
    //  Note that if the event object already exists, the CreateEvent requests
    //  EVENT_ALL_ACCESS access right. If this fails, we try to open
    //  the event object asking for SYNCHRONIZE access only.
    HANDLE sync = CreateEvent (&sa, FALSE, TRUE, TEXT ("Global\\zmq-signaler-port-sync"));
    if (sync == NULL && GetLastError () == ERROR_ACCESS_DENIED)
      sync = OpenEvent (SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, TEXT ("Global\\zmq-signaler-port-sync"));

    win_assert (sync != NULL);

    //  Enter the critical section.
    DWORD dwrc = WaitForSingleObject (sync, INFINITE);
    zmq_assert (dwrc == WAIT_OBJECT_0);

    //  Windows has no 'socketpair' function. CreatePipe is no good as pipe
    //  handles cannot be polled on. Here we create the socketpair by hand.
    *r_ = INVALID_SOCKET; 

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