st

commit 33dfe877d83ba079a6d26cf40e3191396c38393f
parent 8ccab2e68b15e8396effc21fa2ae509b140d7639
Author: Tommi Hirvola <tommi@hirvola.fi>
Date:   Mon,  4 Mar 2024 12:56:30 +0200

set upper limit for REP escape sequence argument

Previously, printf 'L\033[2147483647b' would call tputc('L') 2^31 times,
making st unresponsive. This commit allows repeating the last character
at most 65535 times in order to prevent freezing and DoS attacks.

Diffstat:
M
st.c
 | 
2
+-

1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/st.c b/st.c
@@ -1643,7 +1643,7 @@ csihandle(void)
 			ttywrite(vtiden, strlen(vtiden), 0);
 		break;
 	case 'b': /* REP -- if last char is printable print it <n> more times */
-		DEFAULT(csiescseq.arg[0], 1);
+		LIMIT(csiescseq.arg[0], 1, 65535);
 		if (term.lastc)
 			while (csiescseq.arg[0]-- > 0)
 				tputc(term.lastc);