Vulnerability in Nanopb
CVE-2021-21401
Nanopb is a small code-size Protocol Buffers implementation in ansi C. In Nanopb before versions 0.3.9.8 and 0.4.5, decoding a specifically formed message can cause invalid `free()` or `realloc()` calls if the message type contains an `oneof` field, and the `oneof` directly contains both a pointer field and a non-pointer field. If the message data first contains the non-pointer field and then the pointer field, the data of the non-pointer field is incorrectly treated as if it was a pointer value. Such message data rarely occurs in normal messages, but it is a concern when untrusted data is parsed. This has been fixed in versions 0.3.9.8 and 0.4.5. See referenced GitHub Security Advisory for more information including workarounds.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.
EPSS exploit prediction
EPSS: 0.018 (77.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000
Affected products
- Nanopb — versions >= 0.3.2, <= 0.3.9.7, >= 0.4.0, <= 0.4.4
- Nanopb Project
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/nanopb/nanopb/security/advisories/GHSA-7mv5-5mxh-qg88 (Exploit, Patch, Third Party Advisory)
- github.com/nanopb/nanopb/issues/647 (Exploit, Third Party Advisory, Issue Tracking)
- github.com/nanopb/nanopb/commit/e2f0ccf939d9f82931d085acb6df8e9a182a4261 (Patch, Third Party Advisory)
- github.com/nanopb/nanopb/blob/c9124132a604047d0ef97a09c0e99cd9bed2c818/CHANGELO… (Third Party Advisory, Release Notes)
Frequently asked questions
- What is CVE-2021-21401?
- CVE-2021-21401 is a high-severity vulnerability in Nanopb, classified under Release of Invalid Pointer or Reference. CVSS score: 7.1/10. Published 2021-03-23.
- How severe is CVE-2021-21401?
- High severity. CVSS v3 base score is 7.1 out of 10.
- Is CVE-2021-21401 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.