Blst vulnerable to incorrect results for some inputs in blst_fp_eucl_inverse functionGHSA-x279-68rr-jp4p
Fix: supranational/blst@dd980e7GHSA-x279-68rr-jp4p is a security vulnerability in github.com/supranational/blst. A fix is available for github.com/supranational/blst — see the affected versions and patch details below.
Real-World Exposure
github.com/supranational/blstReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Blst versions v0.3.0 to v0.3.2 can produce the incorrect outputs for some inputs to the blst_fp_eucl_inverse function. This could theoretically result in the creation of an invalid signature from correct inputs. However, fuzzing of higher level functions such as sign and verify were unable to produce incorrect results and there has been no reported occurrences of this issue being encountered in production use.
Description
During the course of differential fuzzing of the blst library by @guidovranken it was discovered that blst would produce the incorrect result for some input values in the inverse function. This was the result of the introduction of a new inversion formula in version v0.3.0. This source of these incorrect outputs was due to two issues:
- The amount of inner loop iterations was not sufficient for the algorithm to converge.
- It was erroneously assumed that the absolute value of the intermediate result would be capped at 767-bits. As a result, some output values were truncated by one bit or the most significant bit was misinterpreted as the sign.
Patches
This issue has been resolved in the v0.3.3 release and users are recommended to upgrade immediately.
References
The software used to uncover this issue can be found here.
Credits
A special thanks to Guido Vranken (@guidovranken) for his discovery and disclosure of this vulnerability.
For more information
If you have any questions or comments about this advisory please email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/supranational/blst | ≥ 0.3.0&&< 0.3.3 | 0.3.3go get github.com/supranational/blst@v0.3.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/supranational/blst, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/supranational/blst to 0.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x279-68rr-jp4p is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-x279-68rr-jp4p in your dependencies?
Find it across Go, including transitive dependencies.