alpine 3.6
access weakness #486


Weakness Breakdown


An access weakness occurs when software does not properly implement permissions that could have unintended consequences if exploited by malicious actors. An example of this weakness is when a default username and password are set by the developer but do not get changed by the system administrator.

Warning code(s):

Ensure that umask is given most restrictive possible setting.

File Name:



The highlighted line of code below is the trigger point of this particular Alpine 3.6 access weakness.


static const char* pid_file_proc(void) {
    return AVAHI_DAEMON_RUNTIME_DIR"/pid";

static int make_runtime_dir(void) {
    int r = -1;
    mode_t u;
    int reset_umask = 0;
    struct passwd *pw;
    struct group * gr;
    struct stat st;

    if (!(pw = getpwnam(AVAHI_USER))) {
        avahi_log_error( "Failed to find user '"AVAHI_USER"'.");
        goto fail;

    if (!(gr = getgrnam(AVAHI_GROUP))) {
        avahi_log_error( "Failed to find group '"AVAHI_GROUP"'.");
        goto fail;

    u = umask(0000);
    reset_umask = 1;

    if (mkdir(AVAHI_DAEMON_RUNTIME_DIR, 0755) < 0 && errno != EEXIST) {
        avahi_log_error("mkdir(\""AVAHI_DAEMON_RUNTIME_DIR"\"): %s", strerror(errno));
        goto fail;

    chown(AVAHI_DAEMON_RUNTIME_DIR, pw->pw_uid, gr->gr_gid);

    if (stat(AVAHI_DAEMON_RUNTIME_DIR, &st) < 0) {
        avahi_log_error("stat(): %s\n", strerror(errno));
        goto fail;

    if (!S_ISDIR(st.st_mode) || st.st_uid != pw->pw_uid || st.st_gid != gr->gr_gid) {
        avahi_log_error("Failed to create runtime directory "AVAHI_DAEMON_RUNTIME_DIR".");
        goto fail;

    r = 0;

    if (reset_umask)
    return r; 

The registered trademark Linux® is used pursuant to a sublicense from the Linux Foundation, the exclusive licensee of Linus Torvalds, owner of the mark on a world­wide basis.