nehkark/CVE-2025-40778

GitHubRepository PoCWriteup

PoC files

6 files

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GitHub
Analysisdeepseek-v4-pro:cloud ·

Technical assessment

The artifact is a technical writeup describing CVE-2025-40778, a DNS cache poisoning vulnerability in BIND 9. It includes a detailed vulnerability description, attack scenarios, mitigation strategies, and references. The repository's README and other text files reference exploit scripts (auth_poison.py, validate_poc_forwarder.py) and show their output, but the actual executable code for these scripts is not included in the supplied evidence packets.

Backdoor review

No backdoor observed in reviewed code

The supplied evidence consists of documentation and configuration files describing a proof-of-concept for CVE-2025-40778, a DNS cache poisoning vulnerability. The text files (CVE-2025-40778.md, README.md, readme.txt, requirements.txt) contain educational explanations, setup instructions, and example command-line invocations for the PoC scripts. No executable code, obfuscated payloads, or concealed backdoor behavior is present in the reviewed text. The PoC scripts themselves (auth_poison.py, validate_poc_forwarder.py) are not included in the text evidence, so their behavior cannot be assessed, but the documentation describes only expected DNS manipulation consistent with the claimed vulnerability. No findings of deceptive or harmful behavior were identified.

ClassificationWriteup
Model confidence95%
AuthenticationNot required
LanguagesMarkdownPlaintext
Target softwareBIND 9
Attack typesDNS cache poisoning
Evidence & reasoningClassification basis · observed behavior · safety review
Technical evidence

Classification basis and observed behavior

Classification basis

The supplied evidence consists entirely of documentation files (CVE-2025-40778.md, README.md, readme.txt, requirements.txt). These files describe the vulnerability, attack scenarios, and mitigation, and reference exploit scripts (auth_poison.py, validate_poc_forwarder.py) but do not contain the source code for those scripts. The content is a substantive technical analysis without executable exploit or scanner code, which matches the definition of a writeup.

CVE-2025-40778.md:1-476README.md:1-265readme.txt:50-55

Requirements

  • A compromised or malicious authoritative nameserver that can inject out-of-zone records into DNS responses.CVE-2025-40778.md:21
  • A vulnerable recursive DNS resolver (BIND 9) that lacks proper bailiwick checking and caches the injected records.CVE-2025-40778.md:31

Observed behavior

  • The writeup describes how a malicious authoritative nameserver can inject unrelated DNS records into a response, which a vulnerable recursive resolver will cache, poisoning its cache for future queries.CVE-2025-40778.md:21CVE-2025-40778.md:31
  • The README shows console output from running the PoC scripts, including a malicious server log indicating a poisoned record was sent and a dig query showing the legitimate answer.README.md:163-167README.md:192-193
Safety-review evidence

Behaviors behind the backdoor verdict

Observables

Contact Information
krakhen@gmail.com, ICQ: 24298753, https://vciso.cloudAuthor contact details provided in documentation; not indicative of backdoor behavior.CVE-2025-40778.md:431-433README.md:38-40
Missing Executable Code
auth_poison.py, validate_poc_forwarder.pyThe PoC scripts are referenced but their source code is not included in the reviewed text evidence; their behavior cannot be verified.readme.txt:51-52CVE-2025-40778.md:380-381
Review boundaries

What the analysis did not establish

  • The evidence packets do not include the content of the auth_poison.py and validate_poc_forwarder.py scripts, which are referenced as the main PoC exploit and validation tool. Only their output and descriptions are present.
  • The packet metadata indicates 2 files were omitted from the text content, which likely correspond to the missing Python scripts.
  • The actual PoC scripts (auth_poison.py, validate_poc_forwarder.py) are not included in the text evidence; their source code was not reviewed. The verdict applies only to the supplied documentation files.
  • Two files (metadata only) were omitted from the text evidence and not analyzed.
Model interpretation

This review is limited to the supplied PoC code and context. It does not assert that the code works or is safe to execute.

Linked vulnerabilities

1