RCTF 2021 challenges & writeups

RCTF is a Jeopardy-style Online Capture The Flag Competition presented by ROIS. The contest is opened to all participants around the world. Teams can compete from any location. No restriction on the number of participants of any team. The Champion Team of RCTF will be invited to The Finals of the 7th Edition of XCTF(the location/date subject to change, qualified teams will be informed when the Finals location/date is confirmed). Other teams can also get the cumulative points to compete for other slots to The Finals of the 7th Edition of XCTF.

Website: https://rctf.rois.io/ Platform: https://rctf2021.xctf.org.cn Telegram: https://t.me/joinchat/kvJLZFUSSsg1NDFl QQ Group: 729402738

Web 5

Challenge	Has
CandyShop #nosql-injection #ssti	files wu 1
Easyphp #url-decode-discrepancy #auth-bypass #double-encoding	files wu 1
VerySafe #caddy-path-traversal #php-fpm #argument-injection	files wu 1
ns_shaft_sql #error-based-sqli #mysql	files wu 1
xss_it #ejs-ssti #xss #xs-leak	files wu 1

Challenge

Has

CandyShop

#nosql-injection #ssti

files wu 1

Easyphp

#url-decode-discrepancy #auth-bypass #double-encoding

files wu 1

VerySafe

#caddy-path-traversal #php-fpm #argument-injection

files wu 1

ns_shaft_sql

#error-based-sqli #mysql

files wu 1

xss_it

#ejs-ssti #xss #xs-leak

files wu 1

Pwn 8

Challenge	Has
Pokemon #tcache-stashing-unlink #heap-overflow #null-byte-bypass	files wu 1
catch_the_frog #integer-overflow #heap-overflow	files wu 1
ezheap #alignment-overflow #negative-index #out-of-bounds (oob)	files wu 1
game #custom-vm #out-of-bounds (oob)	files wu 1
musl #musl-heap #meta-corruption #orw #seccomp	files wu 2
sharing #shared-ptr #refcount-underflow #use-after-free (uaf)	files wu 1
unistruct #stdvariant #iterator-invalidation #use-after-free (uaf)	files wu 1
warmnote #musl-heap #null-byte-overflow #meta-corruption #stack-pivot	files wu 2

Challenge

Has

Pokemon

#tcache-stashing-unlink #heap-overflow #null-byte-bypass

files wu 1

catch_the_frog

#integer-overflow #heap-overflow

files wu 1

ezheap

#alignment-overflow #negative-index #out-of-bounds (oob)

files wu 1

game

#custom-vm #out-of-bounds (oob)

files wu 1

musl

#musl-heap #meta-corruption #orw #seccomp

files wu 2

sharing

#shared-ptr #refcount-underflow #use-after-free (uaf)

files wu 1

unistruct

#stdvariant #iterator-invalidation #use-after-free (uaf)

files wu 1

warmnote

#musl-heap #null-byte-overflow #meta-corruption #stack-pivot

files wu 2

Reverse 5

Challenge	Has
Hi_Harmony #riscv #harmonyos #caesar-cipher	files wu 1
LoongArch #loongarch #instruction-set-reversing	files wu 1
Valgrind #vex-ir #valgrind #caesar-cipher	files wu 1
dht #bruteforce #thread-race #search-pruning	files wu 1
two_shortest #oob-index #free-pascal #got-overwrite	files wu 1

Challenge

Has

Hi_Harmony

#riscv #harmonyos #caesar-cipher

files wu 1

LoongArch

#loongarch #instruction-set-reversing

files wu 1

Valgrind

#vex-ir #valgrind #caesar-cipher

files wu 1

dht