CVE-2020-35859
Out of bounds access in lucet-runtime-internals
An issue was discovered in the lucet-runtime-internals crate before 0.5.1 for Rust. It mishandles sigstack allocation. Guest programs may be able to obtain sensitive information, or guest programs can experience memory corruption.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the lucet-runtime-internals crate before 0.5.1 for Rust. It mishandles sigstack allocation. Guest programs may be able to obtain sensitive information, or guest programs can experience memory corruption.
- Record
CVE-2020-35859- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:P - Weakness
- CWE-125, CWE-787
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the lucet-runtime-internals crate before 0.5.1 for Rust. It mishandles sigstack allocation. Guest programs may be able to obtain sensitive information, or guest programs can experience memory corruption.
- Record
CVE-2020-35859- Updated
- 2026-11-02
EUVDEUVD-2021-1537 No score
An issue was discovered in the lucet-runtime-internals crate before 0.5.1 for Rust. It mishandles sigstack allocation. Guest programs may be able to obtain sensitive information, or guest programs can experience memory corruption.
- Record
EUVD-2021-1537- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3933-wvjf-pcvc
Out of bounds access in lucet-runtime-internals
An embedding using affected versions of lucet-runtime configured to use non-default Wasm globals sizes of more than 4KiB, or compiled in debug mode without optimizations, could leak data from the signal handler stack to guest programs. This can potentially cause data from the embedding host to leak to guest programs or cause corruption of guest program memory. This flaw was resolved by correcting the sigstack allocation logic.
- Record
GHSA-3933-wvjf-pcvc- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-125, CWE-787
- Updated
- 2026-11-02
OSVGHSA-3933-wvjf-pcvc
Out of bounds access in lucet-runtime-internals
An embedding using affected versions of lucet-runtime configured to use non-default Wasm globals sizes of more than 4KiB, or compiled in debug mode without optimizations, could leak data from the signal handler stack to guest programs. This can potentially cause data from the embedding host to leak to guest programs or cause corruption of guest program memory. This flaw was resolved by correcting the sigstack allocation logic.
- Record
GHSA-3933-wvjf-pcvc- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-125, CWE-787
- Updated
- 2026-11-02
OSVRUSTSEC-2020-0004
sigstack allocation bug can cause memory corruption or leak
An embedding using affected versions of lucet-runtime configured to use non-default Wasm globals sizes of more than 4KiB, or compiled in debug mode without optimizations, could leak data from the signal handler stack to guest programs. This can potentially cause data from the embedding host to leak to guest programs or cause corruption of guest program memory.
This flaw was resolved by correcting the sigstack allocation logic.
- Record
RUSTSEC-2020-0004- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
lucet-runtime-internalscrates.io |
before 0.4.3 | 0.4.3 |
lucet-runtime-internalscrates.io |
0.5.0 up to 0.5.1 | 0.5.1 |
lucet-runtime-internalscrates.io |
0.0.0-0 up to 0.4.3, 0.5.0 up to 0.5.1 | 0.4.30.5.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-35859 is a critical vulnerability (CVSS 9.1) in Lucet-runtime-internals Project Lucet-runtime-internals, published January 24, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.52%, the 74th percentile. Fixed in lucet-runtime-internals 0.4.3.