What is the CVSS score of CVE-2021-21777?

CVE-2021-21777 has a CVSS 3.1 base score of 10.0 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H. EPSS exploitation probability: 1.7%.

Is there a public PoC exploit available for CVE-2021-21777?

Yes, a public proof-of-concept exploit is available for CVE-2021-21777. Prioritise patching immediately. EPSS: 1.7%.

Opener CVE-2021-21777

CRITICAL

Out-of-bounds Read (CWE-125)

2021-06-17 talos-cna@cisco.com

Buffer Overflow Information Disclosure Opener

10.0

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

10.0 CRITICAL

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

High

Lifecycle Timeline

CVE Published

Jun 17, 2021 - 11:15 nvd

CRITICAL 10.0

DescriptionNVD

An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A specially crafted network request can lead to an out-of-bounds read.

AnalysisAI

An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Out-of-bounds Read (CWE-125), which allows attackers to read data from memory outside the intended buffer boundaries. An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A specially crafted network request can lead to an out-of-bounds read. Affected products include: Opener Project Opener.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate array indices and buffer lengths. Use memory-safe languages. Enable AddressSanitizer during testing.