23 items with this tag.

WHY2025 [REV] Zenmaster

Analysis of a Base64-encoded ELF execution service, bypassing restrictions, and reverse-engineering AMD microcode to recover the flag (unintended solution).

UMASS CTF [HW] Hidden In Flash

Extracting data from a CAT24C64B EEPROM via custom ATmega328P I2C firmware, dumping its contents, discovering it’s a SWF file, and analyzing it to reveal the hidden flag.

UIUCTF [REV] summarize

A stripped binary hides a flag behind complex modular arithmetic, requiring the discovery of six precise nine-digit integers to unlock it.

UIUCTF [PWN] syscalls

A seccomp-restricted binary forces the use of only safe syscalls—openat, preadv2, dup2, and writev—to craft shellcode that reads flag.txt and prints its contents despite strict syscall filtering.

vsCTF [PWN] SHell Service

Reverse a 64-bit ELF that reads a 10-char password from a tar.gz, then exploit a 0.5s-per-correct-char delay (timing side-channel) with a pwntools solver to recover the flag.

vsCTF [PWN] vs-gateway

Exploitation of a Rust-based Wi-Fi management service by cracking a hardcoded MD5 password and leveraging an unrestricted command injection vulnerability to retrieve the flag through remote shell access and TCP redirection.

Akasec CTF [PWN] Good_trip

Reverse engineering a custom ELF binary with a unique memory leak mechanism. The challenge involved identifying and exploiting a subtle memory leak to retrieve the flag.

L3AK CTF [REV] angry

Analyzed a 64-bit stripped ELF, used Ghidra to dissect its dual-stage password checks (first_check, second_check), and unravelled the complex byte-wise logic checks to pass the “Congratulations!” gate.

L3AK CTF [PWN] oorrww

Exploiting a 64-bit Linux binary with seccomp restrictions using the ORW (Open, Read, Write) technique. The challenge involves leaking addresses encoded as double-precision floats and constructing ROP chains to bypass security measures and retrieve the flag.

UMASS CTF [PWN] bench-225

Exploit a hidden menu via stamina and weight tweaks, use format string overflow and ROP to leak canary, ELF base, write '/bin/sh', then execve shell to grab the flag.

UMASS CTF [rev] free-delivery

Reverse-engineering the Krusty Krab’s “free-delivery” APK: decompiled an Android app (patched by Plankton) with jadx, identified suspicious network traffic and shell command behavior.

b01lers CTF [PWN] easy-note

Leveraged heap vulnerabilities like Use-After-Free and tcache poisoning to leak libc and stack addresses, then exploited arbitrary write to execute system('/bin/sh').