CVE-2020-35903 json
Out of bounds read in dync
published 6y ago modified 4mo ago also GHSA-qxjq-v4wf-ppvh , RUSTSEC-2020-0050 , EUVD-2021-1852
- cvss
- 5.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
An issue was discovered in the dync crate before 0.5.0 for Rust. VecCopy allows misaligned element access because u8 is not always the type in question.
Patch / fix
- crates.io dync 0.5.0
- dync_project dync 0.5.0
Is CVE-2020-35903 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- rustsec.org https://rustsec.org/advisories/RUSTSEC-2020-0050.html referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 2.1 | AV:L/AC:L/Au:N/C:N/I:N/A:P |
| GitHub | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| OSV | 3.1 | 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | dync | <0.5.0 >=0.0.0-0, <0.5.0 |
0.5.0 |
Classification
- Weakness
-
- CWE-125 Out-of-bounds Read
References
-
rustsec.org
/advisories/RUSTSEC-2020-0050.html
web, exploit, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2020-35903
advisory
-
github.com
/elrnv/dync/issues/4
web, report
-
github.com
/elrnv/dync
package
-
crates.io
/crates/dync
package
Sources
- CVE List CVE-2020-35903
- GitHub Advisory GHSA-qxjq-v4wf-ppvh
- NVD CVE-2020-35903
- OSV RUSTSEC-2020-0050
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.