CVE-2021-26843

HIGHCVSS 7.5/10EPSS 1.44%

Last modified

CVE-2021-26843 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An issue was discovered in sthttpd through 2.27.1. On systems where the strcpy function is implemented with memcpy, the de_dotdot function may cause a Denial-of-Service (daemon crash) due to overlapping memory ranges being passed to memcpy. EPSS estimates a 1.44% chance of exploitation in the next 30 days.

Description

An issue was discovered in sthttpd through 2.27.1. On systems where the strcpy function is implemented with memcpy, the de_dotdot function may cause a Denial-of-Service (daemon crash) due to overlapping memory ranges being passed to memcpy. This can triggered with an HTTP GET request for a crafted filename. NOTE: this is similar to CVE-2017-10671, but occurs in a different part of the de_dotdot function.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
1.44%

69.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Sthttpd ProjectSthttpd<= 2.27.1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-26843?
An issue was discovered in sthttpd through 2.27.1. On systems where the strcpy function is implemented with memcpy, the de_dotdot function may cause a Denial-of-Service (daemon crash) due to overlapping memory ranges being passed to memcpy. This can triggered with an HTTP GET request for a crafted filename. NOTE: this is similar to CVE-2017-10671, but occurs in a different part of the de_dotdot function.
How severe is CVE-2021-26843?
CVE-2021-26843 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.44% probability of exploitation in the next 30 days.
How do I fix CVE-2021-26843?
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-2021-26843?

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

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Source: NVD / NIST