Summary
A vulnerability in the add_share
function of the Rewards pallet (part of the ORML repository) can lead to an uncaught Rust panic when handling user-provided input exceeding the u128
range.
Affected Components
- ORML Rewards pallet (
rewards/src/lib.rs
)
- Any Substrate-based chain using ORML Rewards with
add_share
accepting unvalidated large u128
inputs
Technical Details
add_share
performs arithmetic on user-supplied values (add_amount
) of type T::Share
(mapped to u128
in Acala).
- If
add_amount
is large enough (e.g., i128::MAX
), the intermediate result may overflow and panic on the cast to u128
.
- Validation occurs only after arithmetic, enabling a crafted input to trigger an overflow.
Impact
A malicious user submitting a specially crafted extrinsic can cause a panic in the runtime:
- Denial of Service by crashing the node process.
- Potential for invalid blocks produced by validators.
Likelihood
This issue is exploitable in production if there exists at least one rewards pool where reward tokens exceed twice the collateral tokens, allowing sufficiently large multiplication to exceed u128
bounds.
Remediation
Backport
The patch have been backported to following release branches:
- polkadot-stable2407
- polkadot-stable2409
A 1.0.1 patch release is made with this fix.
References
Summary
A vulnerability in the
add_share
function of the Rewards pallet (part of the ORML repository) can lead to an uncaught Rust panic when handling user-provided input exceeding theu128
range.Affected Components
rewards/src/lib.rs
)add_share
accepting unvalidated largeu128
inputsTechnical Details
add_share
performs arithmetic on user-supplied values (add_amount
) of typeT::Share
(mapped tou128
in Acala).add_amount
is large enough (e.g.,i128::MAX
), the intermediate result may overflow and panic on the cast tou128
.Impact
A malicious user submitting a specially crafted extrinsic can cause a panic in the runtime:
Likelihood
This issue is exploitable in production if there exists at least one rewards pool where reward tokens exceed twice the collateral tokens, allowing sufficiently large multiplication to exceed
u128
bounds.Remediation
Backport
The patch have been backported to following release branches:
A 1.0.1 patch release is made with this fix.
References