CVE-2021-33391
CVE-2021-33391 is a critical-severity vulnerability in Htacg Tidy with a CVSS 3.x base score of 9.8. 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-416.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- EPSS exploit prediction: 1% (62nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-416
- Affected product: Htacg Tidy
- Published:
- Last modified:
Description
An issue in HTACG HTML Tidy v5.7.28 allows attacker to execute arbitrary code via the -g option of the CleanNode() function in gdoc.c.
Frequently asked questions
- What is CVE-2021-33391?
- An issue in HTACG HTML Tidy v5.7.28 allows attacker to execute arbitrary code via the -g option of the CleanNode() function in gdoc.c.
- How severe is CVE-2021-33391?
- CVE-2021-33391 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-33391 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-33391?
- CVE-2021-33391 affects Htacg Tidy. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-33391?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2021-33391 published?
- CVE-2021-33391 was published on 2023-02-17 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:htacg:tidy:5.7.28:*:*:*:*:*:*:*
More vulnerabilities in Htacg Tidy
- CVE-2017-17497 — High (CVSS 7.5): In Tidy 5.7.0, the prvTidyTidyMetaCharset function in clean.c allows attackers to cause a denial of service…
- CVE-2017-13692 — High (CVSS 7.5): In Tidy 5.5.31, the IsURLCodePoint function in attrs.c allows attackers to cause a denial of service (Segmentation…
- CVE-2015-5522 — Medium (CVSS 6.8): Heap-based buffer overflow in the ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause…
- CVE-2015-5523 — Medium (CVSS 4.3): The ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause a denial of service (crash)…
- CVE-2025-6498 — Low (CVSS 3.3): A vulnerability classified as problematic has been found in HTACG tidy-html5 5.8.0. Affected is the function…
All CVEs affecting Htacg Tidy →
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- CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
- CVE-2025-24085 — Critical (CVSS 10.0): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3,…
- CVE-2024-43102 — Critical (CVSS 10.0): Concurrent removals of certain anonymous shared memory mappings by using the UMTX_SHM_DESTROY sub-request of…
- CVE-2021-32495 — Critical (CVSS 10.0): Radare2 has a use-after-free vulnerability in pyc parser's get_none_object function. Attacker can read freed memory…