Language: C
Label: vulnerable
CWE: CWE-77 \u2014 Improper Neutralization of Special Elements used in a Command ('Command Injection')
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

Code:
void msetGenericCommand(client *c, int nx) {
    int j;
    int setkey_flags = 0;

    if ((c->argc % 2) == 0) {
        addReplyErrorArity(c);
        return;
    }

    /* Handle the NX flag. The MSETNX semantic is to return zero and don't
     * set anything if at least one key already exists. */
    if (nx) {
        for (j = 1; j < c->argc; j += 2) {
            if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
                addReply(c, shared.czero);
                return;
            }
        }
        setkey_flags |= SETKEY_DOESNT_EXIST;
    }

    for (j = 1; j < c->argc; j += 2) {
        c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
        setKey(c, c->db, c->argv[j], c->argv[j + 1], setkey_flags);
        notifyKeyspaceEvent(NOTIFY_STRING,"set",c->argv[j],c->db->id);
    }
    server.dirty += (c->argc-1)/2;
    addReply(c, nx ? shared.cone : shared.ok);
}