What is the CVSS score of CVE-2021-21401?

CVE-2021-21401 has a CVSS 3.1 base score of 7.1 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L. EPSS exploitation probability: 1.8%.

Is there a public PoC exploit available for CVE-2021-21401?

Yes, a public proof-of-concept exploit is available for CVE-2021-21401. Prioritise patching immediately. EPSS: 1.8%.

Is there a patch available for CVE-2021-21401?

Yes, a patch is available for CVE-2021-21401. Update the affected software to the latest version immediately.

Nanopb CVE-2021-21401

HIGH

Release of Invalid Pointer or Reference (CWE-763)

2021-03-23 security-advisories@github.com

Information Disclosure Nanopb

7.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.1 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

Low

Lifecycle Timeline

CVE Published

Mar 23, 2021 - 18:15 nvd

HIGH 7.1

DescriptionNVD

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.

AnalysisAI

Nanopb is a small code-size Protocol Buffers implementation in ansi C. Rated high severity (CVSS 7.1), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified under CWE-763. 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. Affected products include: Nanopb Project Nanopb.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.