vulnerability / NVI-00014082 / Revision 1
serde_with: KeyValueMap serialization panics on empty sequence or map entries
GitHub lists this reviewed advisory for serde_with. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
serde_with
source listed>= 2.3.0, < 3.21.0
### Summary The public `KeyValueMap` serializer assumes that each mapped element has at least one field or item to use as the map key, but it subtracts `1` from the caller-visible length before validating that assumption. An application that serializes attacker-controlled data through `#[serde_as(as = "KeyValueMap")]` can be crashed by an empty inner sequence or map entry. ### Details The affected public surface includes: - Serialization of `#[serde_as(as = "KeyValueMap")]` values through `serde_json::to_string` or any other Serde serializer` - Public `KeyValueMap` conversions for sequence and map-backed entries` The root cause is: The `KeyValueMap` serializer preallocating `Vec::with_capacity(len - 1)` or `Vec::with_capacity(len.unwrap_or(17) - 1)` before checking that the element actually contains the required first key field or item. The vulnerable data/control flow is: attacker-controlled empty entry -> `serde_json::to_string` -> `KeyValueMap::serialize_as` -> `SeqAsMapSerializer::{serialize_seq,serialize_map}` -> `Vec::with_capacity(len - 1)` or `Vec::with_capacity(len.unwrap_or(17) - 1)` -> panic Relevant source locations: - `serde_with/src/key_value_map.rs
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-7gcf-g7xr-8hxj ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
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