NGINX์šฉ Nemesida WAF Free์˜ ์ƒˆ๋กœ์šด ๋นŒ๋“œ

NGINX์šฉ Nemesida WAF Free์˜ ์ƒˆ๋กœ์šด ๋นŒ๋“œ
์ž‘๋…„์— ์šฐ๋ฆฌ๋Š” ์›น ์• ํ”Œ๋ฆฌ์ผ€์ด์…˜์— ๋Œ€ํ•œ ๊ณต๊ฒฉ์„ ์ฐจ๋‹จํ•˜๋Š” NGINX์šฉ ๋™์  ๋ชจ๋“ˆ์ธ Nemesida WAF Free๋ฅผ ์ถœ์‹œํ–ˆ์Šต๋‹ˆ๋‹ค. ๋จธ์‹ ๋Ÿฌ๋‹ ๊ธฐ๋ฐ˜์˜ ์ƒ์šฉ ๋ฒ„์ „๊ณผ ๋‹ฌ๋ฆฌ ๋ฌด๋ฃŒ ๋ฒ„์ „์€ ์„œ๋ช… ๋ฐฉ์‹๋งŒ์„ ์ด์šฉํ•ด ์š”์ฒญ์„ ๋ถ„์„ํ•œ๋‹ค.

Nemesida WAF 4.0.129 ๋ฆด๋ฆฌ์Šค์˜ ํŠน์ง•

ํ˜„์žฌ ๋ฆด๋ฆฌ์Šค ์ด์ „์— Nemesida WAF ๋™์  ๋ชจ๋“ˆ์€ Nginx Stable 1.12, 1.14 ๋ฐ 1.16๋งŒ ์ง€์›ํ–ˆ์Šต๋‹ˆ๋‹ค. ์ƒˆ ๋ฆด๋ฆฌ์Šค์—๋Š” 1.17๋ถ€ํ„ฐ Nginx Mainline์— ๋Œ€ํ•œ ์ง€์›๊ณผ 1.15.10(R18)๋ถ€ํ„ฐ Nginx Plus์— ๋Œ€ํ•œ ์ง€์›์ด ์ถ”๊ฐ€๋˜์—ˆ์Šต๋‹ˆ๋‹ค.

๋˜ ๋‹ค๋ฅธ WAF๋ฅผ ๋งŒ๋“œ๋Š” ์ด์œ ๋Š” ๋ฌด์—‡์ž…๋‹ˆ๊นŒ?


NAXSI์™€ mod_security๋Š” ์•„๋งˆ๋„ ๊ฐ€์žฅ ์ธ๊ธฐ ์žˆ๋Š” ๋ฌด๋ฃŒ WAF ๋ชจ๋“ˆ์ผ ๊ฒƒ์ž…๋‹ˆ๋‹ค. mod_security๋Š” ์ฒ˜์Œ์—๋Š” Apache2์—์„œ๋งŒ ์‚ฌ์šฉ๋˜์—ˆ์ง€๋งŒ Nginx์—์„œ ์ ๊ทน์ ์œผ๋กœ ํ™๋ณดํ•ฉ๋‹ˆ๋‹ค. ๋‘ ์†”๋ฃจ์…˜ ๋ชจ๋‘ ๋ฌด๋ฃŒ ์˜คํ”ˆ ์†Œ์Šค์ด๋ฉฐ ์ „ ์„ธ๊ณ„์ ์œผ๋กœ ๋งŽ์€ ์‚ฌ์šฉ์ž๋ฅผ ๋ณด์œ ํ•˜๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค. mod_security์˜ ๊ฒฝ์šฐ ๋ฌด๋ฃŒ ๋ฐ ์ƒ์—…์šฉ ์„œ๋ช… ์„ธํŠธ๋ฅผ ์—ฐ๊ฐ„ $500์— ์‚ฌ์šฉํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, NAXSI์˜ ๊ฒฝ์šฐ ๊ธฐ๋ณธ์ ์œผ๋กœ ๋ฌด๋ฃŒ ์„œ๋ช… ์„ธํŠธ๊ฐ€ ์žˆ์œผ๋ฉฐ doxsi์™€ ๊ฐ™์€ ์ถ”๊ฐ€ ๊ทœ์น™ ์„ธํŠธ๋„ ์ฐพ์„ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.

์˜ฌํ•ด ์šฐ๋ฆฌ๋Š” NAXSI ๋ฐ Nemesida WAF Free์˜ ์ž‘๋™์„ ํ…Œ์ŠคํŠธํ–ˆ์Šต๋‹ˆ๋‹ค. ๊ฒฐ๊ณผ์— ๋Œ€ํ•ด ๊ฐ„๋žตํžˆ ์„ค๋ช…ํ•˜๋ฉด ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค.

  • NAXSI๋Š” ์ฟ ํ‚ค์—์„œ ์ด์ค‘ URL ๋””์ฝ”๋”ฉ์„ ์ˆ˜ํ–‰ํ•˜์ง€ ์•Š์Šต๋‹ˆ๋‹ค.
  • NAXSI๋Š” ๊ตฌ์„ฑํ•˜๋Š” ๋ฐ ๋งค์šฐ ์˜ค๋žœ ์‹œ๊ฐ„์ด ๊ฑธ๋ฆฝ๋‹ˆ๋‹ค. ๊ธฐ๋ณธ์ ์œผ๋กœ ๊ธฐ๋ณธ ๊ทœ์น™ ์„ค์ •์€ ์›น ์• ํ”Œ๋ฆฌ์ผ€์ด์…˜ ์ž‘์—…(์Šน์ธ, ํ”„๋กœํ•„ ๋˜๋Š” ์ž๋ฃŒ ํŽธ์ง‘, ์„ค๋ฌธ ์กฐ์‚ฌ ์ฐธ์—ฌ ๋“ฑ) ์‹œ ๋Œ€๋ถ€๋ถ„์˜ ์š”์ฒญ์„ ์ฐจ๋‹จํ•˜๋ฉฐ ์˜ˆ์™ธ ๋ชฉ๋ก์„ ์ƒ์„ฑํ•ด์•ผ ํ•ฉ๋‹ˆ๋‹ค. , ์ด๋Š” ๋ณด์•ˆ์— ๋‚˜์œ ์˜ํ–ฅ์„ ๋ฏธ์นฉ๋‹ˆ๋‹ค. ๊ธฐ๋ณธ ์„ค์ •์˜ Nemesida WAF Free๋Š” ์‚ฌ์ดํŠธ ์ž‘์—… ์ค‘์— ๋‹จ ํ•œ ๋ฒˆ์˜ ์˜คํƒ๋„ ์ˆ˜ํ–‰ํ•˜์ง€ ์•Š์•˜์Šต๋‹ˆ๋‹ค.
  • NAXSI์— ๋Œ€ํ•œ ๊ณต๊ฒฉ ์‹คํŒจ ํšŸ์ˆ˜๋Š” ๋ช‡ ๋ฐฐ ๋” ๋†’์Šต๋‹ˆ๋‹ค.

๋‹จ์ ์—๋„ ๋ถˆ๊ตฌํ•˜๊ณ  NAXSI์™€ mod_security์—๋Š” ์˜คํ”ˆ ์†Œ์Šค์™€ ๋งŽ์€ ์‚ฌ์šฉ์ž๋ผ๋Š” ๋‘ ๊ฐ€์ง€ ์ด์ƒ์˜ ์žฅ์ ์ด ์žˆ์Šต๋‹ˆ๋‹ค. ์šฐ๋ฆฌ๋Š” ์†Œ์Šค ์ฝ”๋“œ ๊ณต๊ฐœ์— ๋Œ€ํ•œ ์•„์ด๋””์–ด๋ฅผ ์ง€์ง€ํ•˜์ง€๋งŒ ์ƒ์šฉ ๋ฒ„์ „์˜ "๋ถˆ๋ฒ• ๋ณต์ œ" ๋ฌธ์ œ๋กœ ์ธํ•ด ์•„์ง ์ด๋ฅผ ์ˆ˜ํ–‰ํ•  ์ˆ˜ ์—†์ง€๋งŒ ์ด๋Ÿฌํ•œ ๋‹จ์ ์„ ๋ณด์™„ํ•˜๊ธฐ ์œ„ํ•ด ์‹œ๊ทธ๋‹ˆ์ฒ˜ ์„ธํŠธ์˜ ๋‚ด์šฉ์„ ์™„์ „ํžˆ ๊ณต๊ฐœํ•˜๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค. ์šฐ๋ฆฌ๋Š” ๊ฐœ์ธ์ •๋ณด ๋ณดํ˜ธ๋ฅผ ์ค‘์š”ํ•˜๊ฒŒ ์ƒ๊ฐํ•˜๋ฉฐ ํ”„๋ก์‹œ ์„œ๋ฒ„๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์ด๋ฅผ ์ง์ ‘ ํ™•์ธํ•  ๊ฒƒ์„ ์ œ์•ˆํ•ฉ๋‹ˆ๋‹ค.

Nemesida WAF ๋ฌด๋ฃŒ์˜ ํŠน์ง•:

  • ์ตœ์†Œํ•œ์˜ False Positive ๋ฐ False Negative ์ˆ˜๋ฅผ ๊ฐ–์ถ˜ ๊ณ ํ’ˆ์งˆ ์„œ๋ช… ๋ฐ์ดํ„ฐ๋ฒ ์ด์Šค์ž…๋‹ˆ๋‹ค.
  • ์ €์žฅ์†Œ์—์„œ ์„ค์น˜ ๋ฐ ์—…๋ฐ์ดํŠธ(๋น ๋ฅด๊ณ  ํŽธ๋ฆฌํ•จ)
  • NAXSI์™€ ๊ฐ™์€ "์—‰๋ง"์ด ์•„๋‹Œ ์‚ฌ๊ฑด์— ๋Œ€ํ•œ ๊ฐ„๋‹จํ•˜๊ณ  ์ดํ•ดํ•˜๊ธฐ ์‰ฌ์šด ์ด๋ฒคํŠธ์ž…๋‹ˆ๋‹ค.
  • ์™„์ „ ๋ฌด๋ฃŒ์ด๋ฉฐ ํŠธ๋ž˜ํ”ฝ ์–‘, ๊ฐ€์ƒ ํ˜ธ์ŠคํŠธ ๋“ฑ์— ์ œํ•œ์ด ์—†์Šต๋‹ˆ๋‹ค.

๊ฒฐ๋ก ์ ์œผ๋กœ WAF์˜ ์„ฑ๋Šฅ์„ ํ‰๊ฐ€ํ•˜๊ธฐ ์œ„ํ•ด ๋ช‡ ๊ฐ€์ง€ ์ฟผ๋ฆฌ๋ฅผ ์ œ๊ณตํ•˜๊ฒ ์Šต๋‹ˆ๋‹ค(๊ฐ ์˜์—ญ(URL, ARGS, ํ—ค๋” ๋ฐ ๋ณธ๋ฌธ)์—์„œ ์‚ฌ์šฉํ•˜๋Š” ๊ฒƒ์ด ์ข‹์Šต๋‹ˆ๋‹ค).

')) un","ion se","lect 1,2,3,4,5,6,7,8,9,0,11#"] ')) union/**/select/**/1,/**/2,/**/3,/**/4,/**/5,/**/6,/**/7,/**/8,/**/9,/**/'some_text',/**/11#"] union(select(1),2,3,4,5,6,7,8,9,0x70656e746573746974,11)#"] ')) union+/*!select*/ (1),(2),(3),(4),(5),(6),(7),(8),(9),(0x70656e746573746974),(11)#"] ')) /*!u%6eion*/ /*!se%6cect*/ (1),(2),(3),(4),(5),(6),(7),(8),(9.),(0x70656e746573746974),(11)#"] ')) %2f**%2funion%2f**%2fselect (1),(2),(3),(4),(5),(6),(7),(8),(9),(0x70656e746573746974),(11)#"] %5B%221807182982%27%29%29%20uni%22%2C%22on
%20sel%22%2C%22ect%201%2C2%2C3%2C4%2C5%2C6%2C7%2C8%2C9%2C%2some_text%27%2C11%23%22%5D
cat /et?/pa?swd
cat /et'c/pa'ss'wd
cat /et*/pa**wd
e'c'ho 'swd test pentest' |awk '{print "cat /etc/pas"$1}' |bas'h
cat /etc/passwd
cat$u+/etc$u/passwd$u
<svg/onload=alert()//

์š”์ฒญ์ด ์ฐจ๋‹จ๋˜์ง€ ์•Š์œผ๋ฉด WAF๊ฐ€ ์‹ค์ œ ๊ณต๊ฒฉ์„ ๋†“์น  ๊ฐ€๋Šฅ์„ฑ์ด ๋†’์Šต๋‹ˆ๋‹ค. ์˜ˆ์ œ๋ฅผ ์‚ฌ์šฉํ•˜๊ธฐ ์ „์— WAF๊ฐ€ ํ•ฉ๋ฒ•์ ์ธ ์š”์ฒญ์„ ์ฐจ๋‹จํ•˜๊ณ  ์žˆ์ง€ ์•Š์€์ง€ ํ™•์ธํ•˜์„ธ์š”.

์ถœ์ฒ˜ : habr.com

์ฝ”๋ฉ˜ํŠธ๋ฅผ ์ถ”๊ฐ€