{"id":476130,"date":"2023-08-09T07:26:52","date_gmt":"2023-08-09T07:26:52","guid":{"rendered":""},"modified":"2023-09-05T11:12:07","modified_gmt":"2023-09-05T11:12:07","slug":"buffer-overflow","status":"publish","type":"wiki","link":"https:\/\/oneproxy.pro\/vn\/wiki\/buffer-overflow\/","title":{"rendered":"Tr\u00e0n b\u1ed9 nh\u1edb"},"content":{"rendered":"<p>Tr\u00e0n b\u1ed9 \u0111\u1ec7m l\u00e0 t\u00ecnh tr\u1ea1ng \u1ee9ng d\u1ee5ng c\u1ed1 g\u1eafng ghi nhi\u1ec1u d\u1eef li\u1ec7u h\u01a1n v\u00e0o m\u1ed9t kh\u1ed1i b\u1ed9 nh\u1edb ho\u1eb7c b\u1ed9 \u0111\u1ec7m so v\u1edbi m\u1ee9c n\u00f3 c\u00f3 th\u1ec3 ch\u1ee9a. S\u1ef1 tr\u00e0n n\u00e0y c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn h\u1ecfng d\u1eef li\u1ec7u li\u00ean quan, khi\u1ebfn \u1ee9ng d\u1ee5ng ho\u1ea1t \u0111\u1ed9ng kh\u00f4ng th\u1ec3 \u0111o\u00e1n tr\u01b0\u1edbc ho\u1eb7c th\u1eadm ch\u00ed b\u1ecb l\u1ed7i. Nghi\u00eam tr\u1ecdng h\u01a1n, l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m c\u00f3 th\u1ec3 b\u1ecb l\u1ee3i d\u1ee5ng \u0111\u1ec3 th\u1ef1c thi m\u00e3 t\u00f9y \u00fd, d\u1eabn \u0111\u1ebfn vi ph\u1ea1m an ninh h\u1ec7 th\u1ed1ng.<\/p>\n<h2>Ngu\u1ed3n g\u1ed1c v\u00e0 c\u00e1c tr\u01b0\u1eddng h\u1ee3p ban \u0111\u1ea7u c\u1ee7a tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/h2>\n<p>Kh\u00e1i ni\u1ec7m tr\u00e0n b\u1ed9 \u0111\u1ec7m c\u00f3 th\u1ec3 b\u1eaft ngu\u1ed3n t\u1eeb nh\u1eefng ng\u00e0y \u0111\u1ea7u l\u1eadp tr\u00ecnh, \u0111\u1eb7c bi\u1ec7t v\u1edbi s\u1ef1 ra \u0111\u1eddi c\u1ee7a c\u00e1c ng\u00f4n ng\u1eef nh\u01b0 C v\u00e0 C++ cho ph\u00e9p thao t\u00e1c tr\u1ef1c ti\u1ebfp v\u1edbi b\u1ed9 nh\u1edb. Tr\u01b0\u1eddng h\u1ee3p l\u1ed7 h\u1ed5ng tr\u00e0n b\u1ed9 \u0111\u1ec7m \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1 r\u1ed9ng r\u00e3i \u0111\u1ea7u ti\u00ean l\u00e0 Internet Worm v\u00e0o n\u0103m 1988. S\u00e2u n\u00e0y khai th\u00e1c l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m trong daemon &#039;ng\u00f3n tay&#039; Unix \u0111\u1ec3 l\u00e2y lan tr\u00ean c\u00e1c m\u1ea1ng, l\u00e2y nhi\u1ec5m sang h\u00e0ng ngh\u00ecn m\u00e1y t\u00ednh. S\u1ef1 c\u1ed1 n\u00e0y \u0111\u00e3 n\u00e2ng cao nh\u1eadn th\u1ee9c c\u1ee7a c\u1ed9ng \u0111\u1ed3ng v\u1ec1 c\u00e1c l\u1ed7 h\u1ed5ng tr\u00e0n b\u1ed9 \u0111\u1ec7m v\u00e0 n\u00f3 \u0111\u00e3 tr\u1edf th\u00e0nh tr\u1ecdng t\u00e2m \u0111\u00e1ng k\u1ec3 trong an ninh m\u1ea1ng k\u1ec3 t\u1eeb \u0111\u00f3.<\/p>\n<h2>\u0110i s\u00e2u v\u00e0o v\u1ea5n \u0111\u1ec1 tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/h2>\n<p>Tr\u00e0n b\u1ed9 \u0111\u1ec7m th\u01b0\u1eddng x\u1ea3y ra trong c\u00e1c ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh kh\u00f4ng c\u00f3 t\u00ednh n\u0103ng ki\u1ec3m tra gi\u1edbi h\u1ea1n t\u00edch h\u1ee3p, ch\u1eb3ng h\u1ea1n nh\u01b0 C v\u00e0 C++. C\u00e1c ng\u00f4n ng\u1eef n\u00e0y cho ph\u00e9p nh\u00e0 ph\u00e1t tri\u1ec3n ph\u00e2n b\u1ed5 m\u1ed9t l\u01b0\u1ee3ng b\u1ed9 nh\u1edb nh\u1ea5t \u0111\u1ecbnh cho c\u00e1c bi\u1ebfn, nh\u01b0ng ch\u00fang kh\u00f4ng t\u1ef1 \u0111\u1ed9ng ng\u0103n c\u00e1c bi\u1ebfn n\u00e0y v\u01b0\u1ee3t qu\u00e1 k\u00edch th\u01b0\u1edbc \u0111\u01b0\u1ee3c ph\u00e2n b\u1ed5. \u0110i\u1ec1u n\u00e0y tr\u1edf n\u00ean c\u00f3 v\u1ea5n \u0111\u1ec1 khi m\u1ed9t ch\u01b0\u01a1ng tr\u00ecnh ghi nhi\u1ec1u d\u1eef li\u1ec7u v\u00e0o b\u1ed9 \u0111\u1ec7m h\u01a1n m\u1ee9c n\u00f3 c\u00f3 th\u1ec3 x\u1eed l\u00fd, d\u1eabn \u0111\u1ebfn tr\u00e0n.<\/p>\n<p>Khi x\u1ea3y ra l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m, d\u1eef li\u1ec7u d\u01b0 th\u1eeba c\u00f3 th\u1ec3 ghi \u0111\u00e8 l\u00ean c\u00e1c v\u00f9ng nh\u1edb l\u00e2n c\u1eadn, l\u00e0m h\u1ecfng ho\u1eb7c thay \u0111\u1ed5i n\u1ed9i dung c\u1ee7a ch\u00fang. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 g\u00e2y ra h\u00e0nh vi kh\u00f4ng mong mu\u1ed1n trong ph\u1ea7n m\u1ec1m, d\u1eabn \u0111\u1ebfn s\u1ef1 c\u1ed1 ho\u1eb7c k\u1ebft qu\u1ea3 kh\u00f4ng ch\u00ednh x\u00e1c. Trong tr\u01b0\u1eddng h\u1ee3p x\u1ea5u nh\u1ea5t, l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m c\u00f3 th\u1ec3 b\u1ecb khai th\u00e1c \u0111\u1ec3 th\u1ef1c thi m\u00e3 t\u00f9y \u00fd, cung c\u1ea5p cho k\u1ebb t\u1ea5n c\u00f4ng quy\u1ec1n ki\u1ec3m so\u00e1t h\u1ec7 th\u1ed1ng m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3.<\/p>\n<h2>C\u01a1 ch\u1ebf b\u00ean trong c\u1ee7a tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/h2>\n<p>B\u1ed9 \u0111\u1ec7m v\u1ec1 c\u01a1 b\u1ea3n l\u00e0 m\u1ed9t kh\u1ed1i b\u1ed9 nh\u1edb li\u1ec1n k\u1ec1 \u0111\u01b0\u1ee3c ph\u00e2n b\u1ed5 \u0111\u1ec3 l\u01b0u gi\u1eef d\u1eef li\u1ec7u. Tr\u00e0n b\u1ed9 \u0111\u1ec7m x\u1ea3y ra khi nhi\u1ec1u d\u1eef li\u1ec7u h\u01a1n m\u1ee9c ph\u00e2n b\u1ed5 ban \u0111\u1ea7u \u0111\u01b0\u1ee3c ghi v\u00e0o kh\u1ed1i b\u1ed9 nh\u1edb n\u00e0y. Vi\u1ec7c tr\u00e0n d\u1eef li\u1ec7u c\u00f3 th\u1ec3 ghi \u0111\u00e8 l\u00ean c\u00e1c v\u1ecb tr\u00ed b\u1ed9 nh\u1edb l\u00e2n c\u1eadn v\u00e0 l\u00e0m gi\u00e1n \u0111o\u1ea1n lu\u1ed3ng th\u00f4ng th\u01b0\u1eddng c\u1ee7a \u1ee9ng d\u1ee5ng.<\/p>\n<p>Trong tr\u01b0\u1eddng h\u1ee3p \u0111i\u1ec3n h\u00ecnh c\u1ee7a cu\u1ed9c t\u1ea5n c\u00f4ng tr\u00e0n b\u1ed9 \u0111\u1ec7m, k\u1ebb t\u1ea5n c\u00f4ng c\u1ed1 t\u00ecnh g\u1eedi d\u1eef li\u1ec7u d\u01b0 th\u1eeba v\u1edbi c\u00e1c m\u1eabu c\u1ee5 th\u1ec3. Khi d\u1eef li\u1ec7u n\u00e0y tr\u00e0n, n\u00f3 c\u00f3 th\u1ec3 ghi \u0111\u00e8 \u0111\u1ecba ch\u1ec9 tr\u1ea3 v\u1ec1 c\u1ee7a h\u00e0m. N\u1ebfu ph\u1ea7n tr\u00e0n \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng ch\u00ednh x\u00e1c, \u0111\u1ecba ch\u1ec9 tr\u1ea3 v\u1ec1 b\u1ecb ghi \u0111\u00e8 c\u00f3 th\u1ec3 tr\u1ecf \u0111\u1ebfn m\u00e3 \u0111\u1ed9c, m\u00e3 n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c bao g\u1ed3m trong d\u1eef li\u1ec7u tr\u00e0n. Lu\u1ed3ng th\u1ef1c thi \u0111\u01b0\u1ee3c chuy\u1ec3n h\u01b0\u1edbng n\u00e0y cung c\u1ea5p cho k\u1ebb t\u1ea5n c\u00f4ng quy\u1ec1n ki\u1ec3m so\u00e1t h\u1ec7 th\u1ed1ng.<\/p>\n<h2>\u0110\u1eb7c \u0111i\u1ec3m ch\u00ednh c\u1ee7a tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/h2>\n<p>Tr\u00e0n b\u1ed9 \u0111\u1ec7m \u0111\u01b0\u1ee3c \u0111\u1eb7c tr\u01b0ng b\u1edfi m\u1ed9t s\u1ed1 t\u00ednh n\u0103ng ch\u00ednh:<\/p>\n<ul>\n<li><strong>Tham nh\u0169ng d\u1eef li\u1ec7u<\/strong>: Vi\u1ec7c tr\u00e0n d\u1eef li\u1ec7u c\u00f3 th\u1ec3 l\u00e0m h\u1ecfng c\u00e1c kh\u00f4ng gian b\u1ed9 nh\u1edb l\u00e2n c\u1eadn, d\u1eabn \u0111\u1ebfn h\u00e0nh vi \u1ee9ng d\u1ee5ng kh\u00f4ng th\u1ec3 \u0111o\u00e1n tr\u01b0\u1edbc.<\/li>\n<li><strong>\u1ee8ng d\u1ee5ng b\u1ecb l\u1ed7i<\/strong>: Tr\u00e0n b\u1ed9 \u0111\u1ec7m th\u01b0\u1eddng khi\u1ebfn \u1ee9ng d\u1ee5ng g\u1eb7p s\u1ef1 c\u1ed1 v\u00ec ch\u00fang l\u00e0m h\u1ecfng c\u1ea5u tr\u00fac d\u1eef li\u1ec7u quan tr\u1ecdng ho\u1eb7c ghi \u0111\u00e8 l\u00ean d\u1eef li\u1ec7u \u0111i\u1ec1u khi\u1ec3n c\u1ee7a \u1ee9ng d\u1ee5ng.<\/li>\n<li><strong>Khai th\u00e1c b\u1ea3o m\u1eadt<\/strong>: L\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m c\u00f3 th\u1ec3 b\u1ecb l\u1ee3i d\u1ee5ng \u0111\u1ec3 th\u1ef1c thi m\u00e3 t\u00f9y \u00fd, cho ph\u00e9p k\u1ebb t\u1ea5n c\u00f4ng gi\u00e0nh quy\u1ec1n ki\u1ec3m so\u00e1t h\u1ec7 th\u1ed1ng.<\/li>\n<\/ul>\n<h2>C\u00e1c lo\u1ea1i tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/h2>\n<p>C\u00f3 nhi\u1ec1u lo\u1ea1i tr\u00e0n b\u1ed9 \u0111\u1ec7m kh\u00e1c nhau, m\u1ed7i lo\u1ea1i c\u00f3 \u0111\u1eb7c \u0111i\u1ec3m v\u00e0 k\u1ef9 thu\u1eadt khai th\u00e1c c\u1ee5 th\u1ec3. M\u1ed9t s\u1ed1 ph\u1ed5 bi\u1ebfn nh\u1ea5t l\u00e0:<\/p>\n<table>\n<thead>\n<tr>\n<th>Ki\u1ec3u<\/th>\n<th>S\u1ef1 mi\u00eau t\u1ea3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Tr\u00e0n ng\u0103n x\u1ebfp<\/td>\n<td>X\u1ea3y ra khi b\u1ed9 \u0111\u1ec7m n\u1eb1m tr\u00ean ng\u0103n x\u1ebfp b\u1ecb tr\u00e0n. \u0110\u00e2y l\u00e0 lo\u1ea1i l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m ph\u1ed5 bi\u1ebfn nh\u1ea5t.<\/td>\n<\/tr>\n<tr>\n<td>Tr\u00e0n \u0111\u1ed1ng<\/td>\n<td>X\u1ea3y ra khi b\u1ed9 \u0111\u1ec7m n\u1eb1m tr\u00ean heap (b\u1ed9 nh\u1edb \u0111\u01b0\u1ee3c c\u1ea5p ph\u00e1t \u0111\u1ed9ng) b\u1ecb tr\u00e0n.<\/td>\n<\/tr>\n<tr>\n<td>Tr\u00e0n s\u1ed1 nguy\u00ean<\/td>\n<td>X\u1ea3y ra khi m\u1ed9t ph\u00e9p t\u00ednh s\u1ed1 h\u1ecdc d\u1eabn \u0111\u1ebfn m\u1ed9t gi\u00e1 tr\u1ecb s\u1ed1 nguy\u00ean qu\u00e1 l\u1edbn \u0111\u1ec3 c\u00f3 th\u1ec3 l\u01b0u tr\u1eef trong ki\u1ec3u s\u1ed1 nguy\u00ean li\u00ean quan.<\/td>\n<\/tr>\n<tr>\n<td>Tr\u00e0n chu\u1ed7i \u0111\u1ecbnh d\u1ea1ng<\/td>\n<td>X\u1ea3y ra khi m\u1ed9t ch\u01b0\u01a1ng tr\u00ecnh kh\u00f4ng x\u00e1c th\u1ef1c \u0111\u00fang c\u00e1ch \u0111\u1ea7u v\u00e0o \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong chu\u1ed7i \u0111\u1ecbnh d\u1ea1ng \u0111\u1ea7u ra, cho ph\u00e9p k\u1ebb t\u1ea5n c\u00f4ng ghi \u0111\u00e8 l\u00ean b\u1ed9 nh\u1edb.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>S\u1eed d\u1ee5ng, v\u1ea5n \u0111\u1ec1 v\u00e0 gi\u1ea3i ph\u00e1p<\/h2>\n<p>L\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m th\u01b0\u1eddng b\u1ecb k\u1ebb t\u1ea5n c\u00f4ng khai th\u00e1c \u0111\u1ec3 ti\u00eam m\u00e3 \u0111\u1ed9c ho\u1eb7c l\u00e0m gi\u00e1n \u0111o\u1ea1n ch\u1ee9c n\u0103ng \u1ee9ng d\u1ee5ng th\u00f4ng th\u01b0\u1eddng. Tuy nhi\u00ean, ch\u00fang kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ee5c \u0111\u00edch s\u1eed d\u1ee5ng c\u00f3 m\u1ee5c \u0111\u00edch ho\u1eb7c h\u1ee3p ph\u00e1p c\u1ee7a c\u00e1c ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh v\u00e0 \u0111\u00e3 c\u00f3 nhi\u1ec1u n\u1ed7 l\u1ef1c \u0111\u1ec3 ng\u0103n ch\u1eb7n s\u1ef1 xu\u1ea5t hi\u1ec7n c\u1ee7a ch\u00fang.<\/p>\n<p>Gi\u1ea3i ph\u00e1p cho v\u1ea5n \u0111\u1ec1 tr\u00e0n b\u1ed9 \u0111\u1ec7m ph\u1ea7n l\u1edbn n\u1eb1m \u1edf c\u00f4ng ngh\u1ec7 v\u00e0 th\u1ef1c ti\u1ec5n l\u1eadp tr\u00ecnh ph\u00f2ng th\u1ee7. V\u00ed d\u1ee5, vi\u1ec7c ki\u1ec3m tra gi\u1edbi h\u1ea1n c\u00f3 th\u1ec3 ng\u0103n ch\u1eb7n t\u00ecnh tr\u1ea1ng tr\u00e0n b\u1ed9 \u0111\u1ec7m b\u1eb1ng c\u00e1ch \u0111\u1ea3m b\u1ea3o r\u1eb1ng d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c ghi v\u00e0o b\u1ed9 \u0111\u1ec7m kh\u00f4ng v\u01b0\u1ee3t qu\u00e1 k\u00edch th\u01b0\u1edbc c\u1ee7a n\u00f3. T\u01b0\u01a1ng t\u1ef1, c\u00e1c bi\u1ec7n ph\u00e1p b\u1ea3o v\u1ec7 b\u1ed9 nh\u1edb kh\u00f4ng th\u1ec3 th\u1ef1c thi c\u00f3 th\u1ec3 ng\u0103n ch\u1eb7n k\u1ebb t\u1ea5n c\u00f4ng th\u1ef1c thi m\u00e3 trong b\u1ed9 \u0111\u1ec7m b\u1ecb tr\u00e0n.<\/p>\n<h2>So s\u00e1nh v\u1edbi c\u00e1c kh\u00e1i ni\u1ec7m t\u01b0\u01a1ng t\u1ef1<\/h2>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 thu\u1eadt ng\u1eef t\u01b0\u01a1ng t\u1ef1 v\u00e0 ch\u00fang kh\u00e1c v\u1edbi l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m nh\u01b0 th\u1ebf n\u00e0o:<\/p>\n<table>\n<thead>\n<tr>\n<th>Thu\u1eadt ng\u1eef<\/th>\n<th>S\u1ef1 mi\u00eau t\u1ea3<\/th>\n<th>S\u1ef1 kh\u00e1c bi\u1ec7t<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/td>\n<td>X\u1ea3y ra khi m\u1ed9t ch\u01b0\u01a1ng tr\u00ecnh c\u1ed1 \u0111\u1ecdc nhi\u1ec1u d\u1eef li\u1ec7u h\u01a1n m\u1ee9c hi\u1ec7n c\u00f3 trong b\u1ed9 \u0111\u1ec7m.<\/td>\n<td>Kh\u00f4ng gi\u1ed1ng nh\u01b0 l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m, l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m th\u01b0\u1eddng kh\u00f4ng d\u1eabn \u0111\u1ebfn c\u00e1c l\u1ed7 h\u1ed5ng b\u1ea3o m\u1eadt.<\/td>\n<\/tr>\n<tr>\n<td>B\u1ed9 nh\u1edb b\u1ecb r\u00f2 r\u1ec9<\/td>\n<td>X\u1ea3y ra khi m\u1ed9t ch\u01b0\u01a1ng tr\u00ecnh kh\u00f4ng qu\u1ea3n l\u00fd vi\u1ec7c ph\u00e2n b\u1ed5 b\u1ed9 nh\u1edb m\u1ed9t c\u00e1ch ch\u00ednh x\u00e1c, d\u1eabn \u0111\u1ebfn gi\u1ea3m b\u1ed9 nh\u1edb kh\u1ea3 d\u1ee5ng theo th\u1eddi gian.<\/td>\n<td>M\u1eb7c d\u00f9 r\u00f2 r\u1ec9 b\u1ed9 nh\u1edb c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m hi\u1ec7u n\u0103ng h\u1ec7 th\u1ed1ng nh\u01b0ng ch\u00fang th\u01b0\u1eddng kh\u00f4ng g\u00e2y ra nguy c\u01a1 t\u1ea5n c\u00f4ng nh\u01b0 tr\u00e0n b\u1ed9 \u0111\u1ec7m.<\/td>\n<\/tr>\n<tr>\n<td>Tr\u00e0n ng\u0103n x\u1ebfp (kh\u00f4ng ph\u1ea3i b\u1ed9 \u0111\u1ec7m)<\/td>\n<td>X\u1ea3y ra khi ng\u0103n x\u1ebfp cu\u1ed9c g\u1ecdi c\u1ee7a ch\u01b0\u01a1ng tr\u00ecnh v\u01b0\u1ee3t qu\u00e1 gi\u1edbi h\u1ea1n c\u1ee7a n\u00f3.<\/td>\n<td>Thu\u1eadt ng\u1eef n\u00e0y kh\u00f4ng li\u00ean quan \u0111\u1ebfn tr\u00e0n b\u1ed9 \u0111\u1ec7m v\u00e0 l\u00e0 k\u1ebft qu\u1ea3 c\u1ee7a vi\u1ec7c \u0111\u1ec7 quy qu\u00e1 m\u1ee9c ho\u1eb7c c\u00e1c bi\u1ebfn ng\u0103n x\u1ebfp l\u1edbn.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Quan \u0111i\u1ec3m v\u00e0 c\u00f4ng ngh\u1ec7 t\u01b0\u01a1ng lai<\/h2>\n<p>Nh\u1eadn th\u1ee9c v\u00e0 t\u00e1c \u0111\u1ed9ng c\u1ee7a l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m \u0111\u00e3 d\u1eabn \u0111\u1ebfn nhi\u1ec1u \u0111\u1ed5i m\u1edbi kh\u00e1c nhau trong l\u1eadp tr\u00ecnh v\u00e0 thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng. C\u00e1c ng\u00f4n ng\u1eef nh\u01b0 Java v\u00e0 Python bao g\u1ed3m t\u00ednh n\u0103ng ki\u1ec3m tra gi\u1edbi h\u1ea1n t\u00edch h\u1ee3p \u0111\u1ec3 ng\u0103n ch\u1eb7n l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m theo thi\u1ebft k\u1ebf. T\u01b0\u01a1ng t\u1ef1, c\u00e1c h\u1ec7 \u0111i\u1ec1u h\u00e0nh hi\u1ec7n \u0111\u1ea1i bao g\u1ed3m c\u00e1c t\u00ednh n\u0103ng nh\u01b0 Ng\u1eabu nhi\u00ean b\u1ed1 c\u1ee5c kh\u00f4ng gian \u0111\u1ecba ch\u1ec9 (ASLR) v\u00e0 Ng\u0103n ch\u1eb7n th\u1ef1c thi d\u1eef li\u1ec7u (DEP) \u0111\u1ec3 gi\u1ea3m thi\u1ec3u vi\u1ec7c khai th\u00e1c l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m.<\/p>\n<p>B\u1ea5t ch\u1ea5p nh\u1eefng ti\u1ebfn b\u1ed9 n\u00e0y, l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m v\u1eabn l\u00e0 m\u1ed1i lo ng\u1ea1i trong c\u00e1c h\u1ec7 th\u1ed1ng d\u1ef1a v\u00e0o m\u00e3 k\u1ebf th\u1eeba ho\u1eb7c ng\u00f4n ng\u1eef c\u1ea5p th\u1ea5p. Do \u0111\u00f3, nghi\u00ean c\u1ee9u v\u00e0 ph\u00e1t tri\u1ec3n \u0111ang di\u1ec5n ra ti\u1ebfp t\u1ee5c c\u1ea3i thi\u1ec7n c\u00e1c k\u1ef9 thu\u1eadt ph\u00e1t hi\u1ec7n v\u00e0 ph\u00f2ng ng\u1eeba.<\/p>\n<h2>M\u00e1y ch\u1ee7 proxy v\u00e0 tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/h2>\n<p>C\u00e1c m\u00e1y ch\u1ee7 proxy, ch\u1eb3ng h\u1ea1n nh\u01b0 c\u00e1c m\u00e1y ch\u1ee7 do OneProxy cung c\u1ea5p, c\u00f3 th\u1ec3 li\u00ean quan \u0111\u1ebfn l\u1ed7i tr\u00e0n b\u1ed9 \u0111\u1ec7m theo hai c\u00e1ch ch\u00ednh. \u0110\u1ea7u ti\u00ean, b\u1ea3n th\u00e2n m\u00e1y ch\u1ee7 proxy c\u00f3 th\u1ec3 c\u00f3 l\u1ed7 h\u1ed5ng tr\u00e0n b\u1ed9 \u0111\u1ec7m n\u1ebfu kh\u00f4ng \u0111\u01b0\u1ee3c m\u00e3 h\u00f3a ch\u00ednh x\u00e1c, c\u00f3 kh\u1ea3 n\u0103ng cho ph\u00e9p k\u1ebb t\u1ea5n c\u00f4ng x\u00e2m ph\u1ea1m m\u00e1y ch\u1ee7. Th\u1ee9 hai, m\u00e1y ch\u1ee7 proxy c\u00f3 kh\u1ea3 n\u0103ng gi\u1ea3m thi\u1ec3u t\u00e1c \u0111\u1ed9ng c\u1ee7a cu\u1ed9c t\u1ea5n c\u00f4ng tr\u00e0n b\u1ed9 \u0111\u1ec7m l\u00ean h\u1ec7 th\u1ed1ng m\u00e1y kh\u00e1ch b\u1eb1ng c\u00e1ch x\u00e1c th\u1ef1c v\u00e0 d\u1ecdn d\u1eb9p \u0111\u1ea7u v\u00e0o ho\u1eb7c ph\u00e1t hi\u1ec7n c\u00e1c m\u1eabu l\u01b0u l\u01b0\u1ee3ng truy c\u1eadp b\u1ea5t th\u01b0\u1eddng cho th\u1ea5y m\u1ed9t cu\u1ed9c t\u1ea5n c\u00f4ng.<\/p>\n<h2>Li\u00ean k\u1ebft li\u00ean quan<\/h2>\n<ul>\n<li><a href=\"https:\/\/cwe.mitre.org\/data\/definitions\/120.html\" target=\"_new\" rel=\"noopener nofollow\">CWE-120: Sao ch\u00e9p b\u1ed9 \u0111\u1ec7m m\u00e0 kh\u00f4ng ki\u1ec3m tra k\u00edch th\u01b0\u1edbc \u0111\u1ea7u v\u00e0o (&#039;Tr\u00e0n b\u1ed9 \u0111\u1ec7m c\u1ed5 \u0111i\u1ec3n&#039;)<\/a><\/li>\n<li><a href=\"https:\/\/owasp.org\/www-community\/attacks\/Buffer_overflow_attack\" target=\"_new\" rel=\"noopener nofollow\">OWASP: T\u1ea5n c\u00f4ng tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/a><\/li>\n<li><a href=\"https:\/\/stackoverflow.com\/questions\/1348470\/why-is-buffer-overflow-dangerous\" target=\"_new\" rel=\"noopener nofollow\">Tr\u00e0n ng\u0103n x\u1ebfp: T\u00ecm hi\u1ec3u v\u1ec1 tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/a><\/li>\n<li><a href=\"https:\/\/www.cisco.com\/c\/en\/us\/about\/security-center\/buffer-overflow-vulnerabilities.html\" target=\"_new\" rel=\"noopener nofollow\">CISCO: L\u1ed7 h\u1ed5ng tr\u00e0n b\u1ed9 \u0111\u1ec7m<\/a><\/li>\n<\/ul>","protected":false},"featured_media":467804,"menu_order":0,"template":"","meta":{"_acf_changed":false,"content-type":"","inline_featured_image":false,"footnotes":""},"class_list":["post-476130","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"faq_title":"Frequently Asked Questions about <mark>Buffer Overflow: A Detailed Examination<\/mark>","faq_items":[{"question":"What is a Buffer Overflow?","answer":"A buffer overflow is a condition where an application tries to write more data to a block of memory, or buffer, than it's designed to hold. This overflow can result in corruption of relevant data, causing an application to behave unpredictably or even crash. It can also be exploited to execute arbitrary code, leading to breaches of system security."},{"question":"When was the first major instance of Buffer Overflow?","answer":"The first major publicized instance of a buffer overflow vulnerability was the Internet Worm in 1988. This worm exploited a buffer overflow in the Unix 'finger' daemon to spread across networks, infecting thousands of computers."},{"question":"How does a Buffer Overflow work?","answer":"When more data than initially allocated is written into a block of memory or a buffer, the overflow of data can overwrite adjacent memory locations. If this overflow is constructed correctly, the overwritten return address can point to malicious code, which may be included in the overflowing data. This redirected execution flow gives the attacker control over the system."},{"question":"What are the key features of Buffer Overflow?","answer":"The key features of a buffer overflow include data corruption, crashing applications, and security exploits. Buffer overflows often cause applications to crash and can be exploited to achieve arbitrary code execution."},{"question":"What are the types of Buffer Overflow?","answer":"There are several types of buffer overflow, each with its own characteristics. They include stack overflow, heap overflow, integer overflow, and format string overflow."},{"question":"How can Buffer Overflow problems be solved?","answer":"The solutions to buffer overflow problems mainly lie in defensive programming practices and technologies. Bounds checking can prevent buffer overflows by ensuring that data written to a buffer does not exceed its size. Similarly, non-executable memory protections can prevent an attacker from executing code in an overflowed buffer."},{"question":"How does Buffer Overflow relate to proxy servers?","answer":"A proxy server itself could have buffer overflow vulnerabilities if not properly coded. Additionally, a proxy server can potentially mitigate the impact of a buffer overflow attack on a client system by validating and sanitizing inputs or detecting abnormal traffic patterns indicative of an attack."},{"question":"What are some future perspectives and technologies related to Buffer Overflow?","answer":"Future perspectives in buffer overflow prevention include innovations in programming and system design. Languages like Java and Python include built-in bounds checking to prevent buffer overflow by design. Modern operating systems include features like Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to mitigate buffer overflow exploits."}]},"_links":{"self":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476130","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/wiki\/476130\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media\/467804"}],"wp:attachment":[{"href":"https:\/\/oneproxy.pro\/vn\/wp-json\/wp\/v2\/media?parent=476130"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}