Mitigate Baron SameEdit (CVE-2021-3156) vulnerability

sles 15.1
race weakness #15


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, a race condition results..

File Name:



The highlighted line of code below is the trigger point of this particular Sles 15.1 race weakness.


#   define REPLACE_CHOWN 1
#  endif
/* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
   to GID (if GID is not -1).  Follow symbolic links.
   Return 0 if successful, otherwise -1 and errno set.
   See the POSIX:2001 specification
   <>.  */
#   define chown rpl_chown
extern int chown (const char *file, uid_t uid, gid_t gid);
#  endif
# endif
# undef chown
# define chown(f,u,g) \
    (GL_LINK_WARNING ("chown fails to follow symlinks on some systems and " \
                      "doesn't treat a uid or gid of -1 on some systems - " \
                      "use gnulib module chown for portability"), \
     chown (f, u, g))

# if !@HAVE_DUP2@
/* Copy the file descriptor OLDFD into file descriptor NEWFD.  Do nothing if
   NEWFD = OLDFD, otherwise close NEWFD first if it is open.
   Return 0 if successful, otherwise -1 and errno set.
   See the POSIX:2001 specification
   <>.  */
extern int dup2 (int oldfd, int newfd);
# endif
# undef dup2
# define dup2(o,n) \
    (GL_LINK_WARNING ("dup2 is unportable - " \
                      "use gnulib module dup2 for portability"), \
     dup2 (o, n))


/* Change the process' current working directory to the directory on which 

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