AC

TCK 243 Entering the Information System: Crime Limit, Defense and Typical Scenarios

TL;DR

TCK m.243 bilişim sistemine girme suçunda yetkisizlik + bilinç + irade şart; "test amaçlı erişim", "açık sistem", "izinli pen-test" istisnaları savunmaya açık.

15 Şubat 2026 Ceza Hukuku 3 dk okuma 8 görüntülenme Son güncelleme: 9 Mayıs 2026

TCK m.243 entering the information system; "lack of authority" is the most critical element. Pen-test permission, bug bounty, open system defenses are valid.

Elements of the crime

  • Information system: broad definition interpreted by law (PC, server, network, device, IoT).
  • Enter: gaining access; Even just the outer layer.
  • Lack of authority: absence of system owner permission.
  • Consciousness and will: deliberately + knowingly.

Punishment and qualified situations

  • Basic: 1-3 years imprisonment + criminal fine.
  • Data acquisition: qualified (3-7 years).
  • Data deletion/alteration: aggravating.
  • Bank/credit system: Turkish Penal Code 244-245.

Defense strategies

  • Permitted pen-test: Contract + scope + date.
  • Bug bounty: Company public program (HackerOne).
  • Open system: Public web control, robots.txt permission.
  • Non-intentional: Accidental access, automatic script.
  • Reason for compliance with the law: Computer forensics (CMK 134), judicial decision.
  • Typical scenarios

    • Guess → entering social media account password: TCK 243 + 244.
    • The former employee still knows the password: TCK 243 as the authorization expires.
    • System outside the scope of pen-test: TCK 243 (contract detail is critical).
    • Seeing files in Public S3 bucket: commented (Supreme Court is not clear yet).

    Frequently asked questions

    I entered my wife's Instagram by guessing her password; crime?

    Yes, TCK article 243. The reason for committing a crime against the spouse in the divorce; In addition, TCK Article 134 (violation of private life). A trump card in both criminal and divorce proceedings.

    I gave permission for pen-test, but the client complained again?

    Written contract + scope document is required. If there is no contract, the "permission defence" is weakened. Preliminary agreement + certified pen-tester (OSCP, CEH) recommended.

    I noticed that my company server was open and I warned; crime?

    "Ethical hacker" attitude; The elements of TCK 243 (conscious + unauthorized) still occur. However, reductions in sentencing and non-prosecution are common. It is safe to work with "Disclosure policy".

    Anyone else's email was opened with Forgot password; What is my responsibility?

    Accidentally, his comment is not clear. If you use the account (reading content, sending messages) TCK 243 + 244. You must exit immediately and return the password.

    I found a vulnerability in the system other than the bug bounty program; what to do?

    Do not interfere; Notify the company by email. If the company does not respond, CERT.tr (TR-CERT) notification. Individual disclosure (full disclosure) carries criminal risk.

    Relevant legislation

    • TCK art.243-245 — Basic articles of cyber crimes.
    • TCK art.158/1-f — Qualified fraud (information tool).
    • CMK article 134 — Search for digital evidence.
    • 5651 SK — Access blocking and content removal.
    • Budapest Cybercrime Convention — Türkiye is a party; international cooperation.
    Legal notice: This article is for general information purposes; A meeting with a lawyer is required for a concrete case. Durations, rates and application are shaped by jurisprudence; Check the current legislation before applying.

    Kaynaklar ve referanslar

    Kaynaklar

    TCK 243 Bilişim Sistemine Girme: Suç Sınırı, Savunma ve Tipik Senaryolar içeriği hazırlanırken resmi mevzuat ve yüksek yargı kaynakları esas alınmıştır.

    Telif bildirimi This content and all related Q&A texts are protected under Turkish Copyright Law No. 5846. Unauthorized copying, reproduction, publication, adaptation, bulk extraction, or commercial use is prohibited; legal and criminal remedies are reserved in case of infringement.

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