CTF
I played Newbie CTF which was held from November 2nd to 3rd in zer0pts. The CTF had some problems in their challenges, servers, and so on but I enjoyed it. We got 15849pts and reached 1st place. Here I'm going to write the solutions for pw…
I played hack.lu CTF 2019 in zer0pts. Although I couldn't play it full-time as it was in weekdays, I managed to solve some challenges after school. We got 1709 points and reached 27th place. It was a fun CTF and I enjoyed it. Thank you for…
SECCON Online 2019 Qualificationが10月19日の15:00(JST)から24時間開催されました。 今年はNaruseJunで参加し、全体で5位でした。 1時間程度しか寝ていないので疲れましたが、オンサイトでわいわい解くのは楽しかったです。通したフラグは合計で1736点でし…
はじめに 2019年に入ってからHouse of Corrosionというヒープ系exploitテクニックが公開されたのですが、全然文献が無いのでまとめようと思います。 結構使えると思うし元記事の考察もよく書かれているので個人的に好きな手法です。 ただ、説明が並んでいる…
SquareCTF had been held from October 11th to 17th (in JST) and I played it in zer0pts. We got 6450 points and kept 7th place. There are many good challenges and I enjoyed them! Thank you for hosting the CTF :) [Reversing 700pts] Aesni [Cry…
はじめに 名前だけ知ってたのですが内容は全然知らなかったのでまとめます。 ヒープ問を解くときは通常freeによりチャンクをtcacheやbinに繋げるのですが、中にはdelete系の機能が用意されていなかったりfreeの回数に制限があったりという問題があります。 …
Layer7 CTF had been held from October 6th to 7th. It's a sole-play CTF and I played it as ptr-yudai. There were so many challenges that I couldn't even check all of them, especially web challenges. I got 1711pts and kept 4th place. [Pwn 10…
SEC-T CTF 2019 had been held from September 18th, 15:00 to 19th, 21:00 UTC. I played this CTF in zer0pts and we reached 6th place with 4485pts. It was a really nice CTF and I learned a lot. Thank you for hosting the CTF! [misc 79pts] sanit…
TokyoWesterns CTF 5th 2019が日本時間で8/31 09:00から9/02 09:00まで開催されました。 私はチームHarekazeとして参加し、Harekazeは1481点を獲得して33位でした。 そのうち5問を私は解いたので、そのwriteupを書こうと思います。 [Pwn 78pts] nothing more…
はじめに yoshikingがセキュリティキャンプに落ち、私もチューターに落ちたのでチームinsecureと阪大からの2人ほどで08/17と08/18にyoshi-campという名の勉強会を開いています。 やる場所が定まらなくて困っていたのですが、つてを辿って阪大の良いお部屋を…
RedpwnCTF 2019 had been held from Aug 12th to 16th and I played this CTF in zer0pts. We got 4433pts and reached 29th place. I gained 3605pts, solving mostly pwn and some forensics, misc, crypto, rev challs. In this post I'll write only abo…
I played CyBRICS CTF 2019 in zer0pts. Our team got 386pts and reached 69th place. It's not a good result but I really enjoyed the CTF as there were many well-designed challenges. [Forensics 67pts] Disk Data [Cyber 50pts] QShell [Network 10…
後半戦： 2019年のpwn問を全部解くチャレンジ【後半戦】 - CTFするぞ まえがき (2019年3月記) 最近CTFに出るとそこそこ良い成績が残せる一方，チームのpwn担当として実力不足を感じています． そこで，pwn苦手意識を克服すべく本日2019年3月13日から，2019年…
ISITDTU CTF 2019 took place from June 29th for 25 hours. I played this CTF in zer0pts and we reached the 10th place. Thank you for holding the CTF. I enjoyed it :-) [Pwn 395] iz_heap_lv1 [Pwn 908] Tokenizer [Pwn 738] babyshellcode [Cryptog…
Midnight Sun CTF 2019 Finalにdcuaで参加し、14チーム中8位でした。 チームメンバーにpwnerがいたので私はrevとhardwareを中心に取り組みました。 いろんな人とお話できて楽しかったです。 取り組んだ問題たち：https://bitbucket.org/ptr-yudai/writeups/s…
I played HSCTF 6 in yoshikingdom and our team reached 11th place. I didn't plan to play this CTF but @y05h1k1ng suggested us to play this one as a joke (not in ordinary team) because it was about to the end of the CTF. So, 11th place in ha…
Facebook CTF 2019 had been held from June 1st 00:00 UTC to June 2nd 00:00 UTC. I played this CTF as a member of zer0pts. We got 9372pts and reached 18th place. I solved several challs and gained 4718pts. The CTF was pretty hard but I reall…
はじめに 数カ月前から始めた鬼のpwn特訓により最近CTFでもヒープ系問題に挑戦できるようになりつつあるのですが、たまにShow機能がない(=一見libcのアドレスがリークできない)ヒープ系問題が出ます。 HITCONのbabytcacheという問題のwriteupを読んでstdout…
5月25日(土)15:00から24時間開催されたSECCON Beginners CTF 2019にzer0ptsのメンバーで参加しました。 大会の存在をすっかり忘れていたので途中から参加しましたが、担当分野は無事全部解くことができました。 初心者向けながら典型とは外れたものもあり、…
5月18日の15時から24時間Harekaze CTF 2019が開催されました。 私はチームYokosuka Hackersとして参加し、チーム全体で3060ptsを獲得して1位でした。 なんとフラグを通したのは2問だけという失態ですが、今回はみんなで情報共有して協力しながらという感じだ…
DEF CON CTF 2019 Qualfier had been held this weekend and I played this CTF with team dcua. We got 1347 in total and reached the 35th place. I enjoyed it but I'm not convinced the scoring system of speedrun challs. Anyway, the quality of th…
Pwnが1問だけあったのでやりました。 [Pwn 268pts] 和暦 説明文：西暦を和暦に変換してくれるよ サーバ：nc wareki-o-reiwa.seccon.jp 36294 64ビットバイナリがもらえます。 $ checksec wareki [*] 'wareki' Arch: 64 bits (little endian) NX: NX enabled …
This CTF took place from April 27th to 29th and I played this one as a member of zer0pts. We got 2570pts and reached the 36th place. Thank you for organizing the CTF. [Pwn 155] quicksort [Pwn 238] girlfriend [Crypto 206] babyprng [Crypto 2…
I played angstromCTF 2019 Quals as a member of team zer0pts. It had been held for 1 week beggining on April 19th. We got 3730pts and reached the 8th place. I was mostly working on pwn challs but also solved another categories and got 1300p…
追記[2019/04/24] この記事を見た運営の方から連絡があり、状況を丁寧に説明してくださいました。 私は説明が下手なので重要な部分だけを翻訳してそのまま書きます。 しばらく前に自称韓国国籍のCTFプレイヤーがCTFの作問を手伝うと申し出ました。 我々は彼…
はじめに 4月17日の13:30から19:30までCPCTFが開催されました。 東京工業大学デジタル創作同好会traPによるCTF+競プロで、東工大の新入生向けに開かれているっぽいです。 私は編入生なので新入生に含まれませんでしたが、ずっとオンサイトで参加していました…
Midnightsun CTF 2019 took place from April 5th, 16:00 to April 6th, 16:00 UTC. This CTF is organized by HackingForSoju, a high level Swedish CTF team. I played this CTF as a member of team dcua. We got 7640pts in total and won the 1st plac…
Sunshine CTF 2019 took place from 30 March, 9:00 AM to 31 March, 9:00 PM EST. I played this CTF in zer0pts and got 1350pts out of the 3255pts we gained. Thanks @SunshineCTF for holding a CTF. [Pwn 50] Return To Mania [Pwn 200] CyberRumble …
Securinets CTF Quals 2019 took place from 24th March, 02:00 JST for 24 hours. Our new team zer0pts got 23393pts and stood 2nd place. I solved 9 challenges and got 7570pts. Thank you Securinets CTF for the great challs! [Foren 200pts] Easy …
Teaser CONFidence 2019 CTF took place from 16 March, 11:00 to 17 March, 11:00 UTC. This CTF was organized by p4, a famous Polish team. Since my usual team members were busy, I played this CTF with the members of team Invaders. We got 762pt…
