gweb: Fix OOB write in received_data()

There is a mismatch of handling binary vs. C-string data with memchr
and strlen, resulting in pos, count, and bytes_read to become out of
sync and result in a heap overflow.  Instead, do not treat the buffer
as an ASCII C-string. We calculate the count based on the return value
of memchr, instead of strlen.

Fixes: CVE-2022-32292

1 files changed, 1 insertions, 1 deletions

diff --git a/gweb/gweb.c b/gweb/gweb.c
index 12fcb1d8..13c6c5f2 100644
--- a/gweb/gweb.c
+++ b/gweb/gweb.c
@@ -918,7 +918,7 @@ static gboolean received_data(GIOChannel *channel, GIOCondition cond,
 		}
 
 		*pos = '\0';
-		count = strlen((char *) ptr);
+		count = pos - ptr;
 		if (count > 0 && ptr[count - 1] == '\r') {
 			ptr[--count] = '\0';
 			bytes_read--;