ts-asn1-der has Incorrect DER Encoding of Numbers Leading to Denial of Service and Incorrect Value Representation
Moderate severity
GitHub Reviewed
Published
Apr 6, 2025
in
ApelegHQ/ts-asn1-der
•
Updated Apr 8, 2025
Description
Published to the GitHub Advisory Database
Apr 7, 2025
Reviewed
Apr 7, 2025
Published by the National Vulnerability Database
Apr 7, 2025
Last updated
Apr 8, 2025
Impact
Incorrect
numberDER encoding can lead to denial on service for absolute values in the range2**31--2**32 - 1. The arithmetic in thenumBitLendidn'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,
numberencoding 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
Asn1Integerto ensure that they are not smaller than-2**31 + 1and no larger than2**31 - 1. AlthoughAsn1Integersupportsbigintinputs, some additional implementation issues make usingbigintas 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
Asn1Integercan be provided as a buffer to be used directly. Note that this requires computing the correct DER encoding externally.References
N/A
References