CVE-2021-26843
CVE-2021-26843 is a high-severity vulnerability in Sthttpd Project Sthttpd with a CVSS 3.x base score of 7.5. 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-119.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 5.0
- EPSS exploit prediction: 1% (70th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-119
- Affected product: Sthttpd Project Sthttpd
- Published:
- Last modified:
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.
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 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2021-26843 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-26843?
- CVE-2021-26843 affects Sthttpd Project Sthttpd. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-26843?
- 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-2021-26843 published?
- CVE-2021-26843 was published on 2021-02-07 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:sthttpd_project:sthttpd:*:*:*:*:*:*:*:*
More vulnerabilities in Sthttpd Project Sthttpd
- CVE-2017-10671 — High (CVSS 7.8): Heap-based Buffer Overflow in the de_dotdot function in libhttpd.c in sthttpd before 2.27.1 allows remote attackers to…
All CVEs affecting Sthttpd Project Sthttpd →
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