alpine 3.9
race weakness #29


Weakness Breakdown


A race condition exists when parallel code accesses shared data without proper coordination. An attack that uses a race-condition weakness takes advantage of the unsafe data access to manipulate how one of the parallel sections of code reacts. Even though each process runs as intended, the outcome is unexpected. For example, consider a bank service that depends on an encryption key that it reads from a known location. An independent cryptography service is responsible for generating the key and placing it where the bank is expected to read it in a timely manner. If the bank and cryptography services do not coordinate with each other, then the bank may read a blank encryption key before cryptography writes the key to the location. This can effectively turn off all encryption for the bank without either service, or the administrator, knowing that something has gone wrong.

Warning code(s):

This accepts filename arguments; if an attacker can move those files or change the link content, a race condition results. Also, it does not terminate with ASCII NUL..

File Name:



The highlighted line of code below is the trigger point of this particular Alpine 3.9 race weakness.

 /* TCP-MIB */
typedef struct {
    sigar_uint64_t active_opens;
    sigar_uint64_t passive_opens;
    sigar_uint64_t attempt_fails;
    sigar_uint64_t estab_resets;
    sigar_uint64_t curr_estab;
    sigar_uint64_t in_segs;
    sigar_uint64_t out_segs;
    sigar_uint64_t retrans_segs;
    sigar_uint64_t in_errs;
    sigar_uint64_t out_rsts;
} sigar_tcp_t;

sigar_tcp_get(sigar_t *sigar,
              sigar_tcp_t *tcp);

typedef struct {
    sigar_uint64_t null;
    sigar_uint64_t getattr;
    sigar_uint64_t setattr;
    sigar_uint64_t root;
    sigar_uint64_t lookup;
    sigar_uint64_t readlink;
    sigar_uint64_t read;
    sigar_uint64_t writecache;
    sigar_uint64_t write;
    sigar_uint64_t create;
    sigar_uint64_t remove;
    sigar_uint64_t rename;
    sigar_uint64_t link;
    sigar_uint64_t symlink;
    sigar_uint64_t mkdir;
    sigar_uint64_t rmdir;
    sigar_uint64_t readdir;
    sigar_uint64_t fsstat;
} sigar_nfs_v2_t;

typedef sigar_nfs_v2_t sigar_nfs_client_v2_t;
typedef sigar_nfs_v2_t sigar_nfs_server_v2_t;

sigar_nfs_client_v2_get(sigar_t *sigar,
                        sigar_nfs_client_v2_t *nfs);

sigar_nfs_server_v2_get(sigar_t *sigar,
                        sigar_nfs_server_v2_t *nfs);

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