Mitigate Baron SameEdit (CVE-2021-3156) vulnerability

sles 15.2
buffer weakness #60

5

Weakness Breakdown


Definition:

Buffer overflows are one of the most well-known software vulnerabilities. Even though most developers know what buffer overflows are, attacks against the vulnerabilities are common in both legacy and newer applications. A classic buffer overflow exploit begins with the attacker sending data to a program, which it then stores in an undersized stack buffer. Besides stack buffer overflows, other kinds of buffer overflows include heap overflows, off-by-one errors and many others. Learn more about buffer overflows on OWASP attack index.

Warning code(s):

Does not check for buffer overflows.

File Name:

ruby-2.5.8/ext/ripper/ripper.c

Context:

The highlighted line of code below is the trigger point of this particular Sles 15.2 buffer weakness.

     int linenum;
    int column;
    int nonspc;
    struct token_info *next;
} token_info;

typedef struct rb_strterm_struct rb_strterm_t;

/*
    Structure of Lexer Buffer:

 lex_pbeg      tokp         lex_p        lex_pend
    |           |              |            |
    |-----------+--------------+------------|
                |<------------>|
                     token
*/
struct parser_params {
    rb_imemo_alloc_t *heap;

    YYSTYPE *lval;

    struct {
	rb_strterm_t *strterm;
	VALUE (*gets)(struct parser_params*,VALUE);
	VALUE input;
	VALUE prevline;
	VALUE lastline;
	VALUE nextline;
	const char *pbeg;
	const char *pcur;
	const char *pend;
	const char *ptok;
	long gets_ptr;
	enum lex_state_e state;
	int paren_nest;
	int lpar_beg;
	int brace_nest;
    } lex;
    stack_type cond_stack;
    stack_type cmdarg_stack;
    int tokidx;
    int toksiz;
    int tokline;
    int heredoc_end;
    int heredoc_indent;
    int heredoc_line_indent;
    char *tokenbuf;
    struct local_vars *lvtbl;
    int line_count; 

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