fedora 24
format weakness #69

4

Weakness Breakdown


Definition:

A format string exploit occurs when the data of an input string is evaluated as a command by the program. This class of attacks is very similar to buffer overflows since an attacker could execute code, read the stack or cause new behaviors that compromise security. Learn more about format string attacks on OWASP attack index.

Warning code(s):

If format strings can be influenced by an attacker, they can be exploited.

File Name:

SuperLU_4.3/TESTING/cdrive.c

Context:

The highlighted line of code below is the trigger point of this particular Fedora 24 format weakness.

     wwork   = complexCalloc( SUPERLU_MAX(m,n) * SUPERLU_MAX(4,nrhs) );

    for (i = 0; i < n; ++i) perm_c[i] = pc_save[i] = i;
    options.ColPerm = MY_PERMC;

    for (imat = fimat; imat <= nimat; ++imat) { /* All matrix types */
	
	if ( imat ) {

	    /* Skip types 5, 6, or 7 if the matrix size is too small. */
	    zerot = (imat >= 5 && imat <= 7);
	    if ( zerot && n < imat-4 )
		continue;
	    
	    /* Set up parameters with CLATB4 and generate a test matrix
	       with CLATMS.  */
	    clatb4_(path, &imat, &n, &n, sym, &kl, &ku, &anorm, &mode,
		    &cndnum, dist);

	    clatms_(&n, &n, dist, iseed, sym, &rwork[0], &mode, &cndnum,
		    &anorm, &kl, &ku, "No packing", Afull, &lda,
		    &wwork[0], &info);

	    if ( info ) {
		printf(FMT3, "CLATMS", info, izero, n, nrhs, imat, nfail);
		continue;
	    }

	    /* For types 5-7, zero one or more columns of the matrix
	       to test that INFO is returned correctly.   */
	    if ( zerot ) {
		if ( imat == 5 ) izero = 1;
		else if ( imat == 6 ) izero = n;
		else izero = n / 2 + 1;
		ioff = (izero - 1) * lda;
		if ( imat < 7 ) {
		    for (i = 0; i < n; ++i) Afull[ioff + i] = zero;
		} else {
		    for (j = 0; j < n - izero + 1; ++j)
			for (i = 0; i < n; ++i)
			    Afull[ioff + i + j*lda] = zero;
		}
	    } else {
		izero = 0;
	    }

	    /* Convert to sparse representation. */
	    sp_cconvert(n, n, Afull, lda, kl, ku, a, asub, xa, &nnz);

	} else { 

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