GHSA-p4qw-7j9g-5h53
ts-asn1-der has Incorrect DER Encoding of Numbers Leading to Denial of Service and Incorrect Value Representation
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @apeleghq/asn1-der | < 1.0.4 | 1.0.4 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
Incorrect `number` DER encoding can lead to denial on service for absolute values in the range `2**31` -- `2**32 - 1`. The arithmetic in the `numBitLen` didn't take into account that values in this range could result in a negative result upon applying the `>>` operator, leading to an infinite loop.
In addition, `number` encoding had a few other issues that resulted it in it not encoding values correctly.
### Patches
The issue is patched in version `1.0.4`. Users are recommended to upgrade as soon as possible.
### Workarounds
If upgrading is not an option, the issue can be mitigated by validating inputs to `Asn1Integer` to ensure that they are not smaller than `-2**31 + 1` and no larger than `2**31 - 1`. Although `Asn1Integer` supports `bigint` inputs, some additional implementation issues make using `bigint` as a mitigation inviable, as it will result in incorrect values.
If upgrading is not an option and range checks are impractical or undesirable, input to `Asn1Integer` can be provided as a buffer to be used directly. Note that this requires computing the correct DER encoding externally.
### References
N/A
References
External links from the advisory. They lead to third-party sites.