CVE-2020-24837

Name: CVE-2020-24837
Creator: NVD / NIST
Published: 2021-02-10T16:15:13.63+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.57%

Last modified Jun 17, 2026

CVE-2020-24837 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An integer underflow has been found in the latest version of ZCFees. The variables 'currPeriodIdx' and 'lastPeriodExecIdx' are both unsigned integers, and the result of the minus operation may be a negative integer which leads to an underflow. EPSS estimates a 1.57% chance of exploitation in the next 30 days.

Description

An integer underflow has been found in the latest version of ZCFees. The variables 'currPeriodIdx' and 'lastPeriodExecIdx' are both unsigned integers, and the result of the minus operation may be a negative integer which leads to an underflow. The attackers can modify the current timestamp of the transaction somehow and block the execution of the process function.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.57%

72.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-191

Affected Software

Vendor	Product	Versions
Zcfees Project	Zcfees	All versions

References

https://etherscan.io/address/0x9d79c6e2a0222b9ac7bfabc447209c58fe9e0dcc#codePatch, Third Party Advisory
https://etherscan.io/address/0x9d79c6e2a0222b9ac7bfabc447209c58fe9e0dcc#codePatch, Third Party Advisory

Timeline

Published: Feb 10, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-24837?

How severe is CVE-2020-24837?

CVE-2020-24837 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.57% probability of exploitation in the next 30 days.

How do I fix CVE-2020-24837?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-24837?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST