How severe is CVE-2020-7877?

CVE-2020-7877 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-7877 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-7877?

CVE-2020-7877 primarily affects Mastersoft Zook Agent. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-7877?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-7877 published?

CVE-2020-7877 was published on 2021-09-07 and last updated on 2026-06-17.

CVE-2020-7877

CVE-2020-7877 is a high-severity vulnerability in Mastersoft Zook Agent with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: High (CVSS 3.x base score 8.0)
CVSS v2: 6.5
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Mastersoft Zook Agent
Published: 2021-09-07
Last modified: 2026-06-17

Description

A buffer overflow issue was discovered in ZOOK solution(remote administration tool) through processing 'ConnectMe' command while parsing a crafted OUTERIP value because of missing boundary check. This vulnerability allows the attacker to execute remote arbitrary command.

Frequently asked questions

What is CVE-2020-7877?: A buffer overflow issue was discovered in ZOOK solution(remote administration tool) through processing 'ConnectMe' command while parsing a crafted OUTERIP value because of missing boundary check. This vulnerability allows the attacker to execute remote arbitrary command.
How severe is CVE-2020-7877?: CVE-2020-7877 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-7877 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-7877?: CVE-2020-7877 primarily affects Mastersoft Zook Agent. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-7877?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-7877 published?: CVE-2020-7877 was published on 2021-09-07 and last updated on 2026-06-17.

References

https://www.boho.or.kr/krcert/secNoticeView.do?bulletin_writing_sequence=36216

Affected products (2)

cpe:2.3:a:mastersoft:zook_agent:2.0.6.1:*:*:*:*:*:*:*
cpe:2.3:a:mastersoft:zook_viewer:2.0.4.6:*:*:*:*:*:*:*

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