How severe is CVE-2021-33484?

CVE-2021-33484 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 high, integrity none, and availability none.

Is CVE-2021-33484 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33484?

CVE-2021-33484 affects Onyaktech Comments Pro Project Onyaktech Comments Pro. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33484?

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-2021-33484 published?

CVE-2021-33484 was published on 2021-09-07 and last updated on 2026-06-17.

CVE-2021-33484

CVE-2021-33484 is a high-severity vulnerability in Onyaktech Comments Pro Project Onyaktech Comments Pro 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-798.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-798
Affected product: Onyaktech Comments Pro Project Onyaktech Comments Pro
Published: 2021-09-07
Last modified: 2026-06-17

Description

An issue was discovered in CommentsService.ashx in OnyakTech Comments Pro 3.8. An attacker can download a copy of the installer, decompile it, and discover a hardcoded IV used to encrypt the username and userid in the comment POST request. Additionally, the attacker can decrypt the encrypted encryption key (sent as a parameter in the comment form request) by setting this encrypted value as the username, which will appear on the comment page in its decrypted form. Using these two values (combined with the encryption functionality discovered in the decompiled installer), the attacker can encrypt another user's ID and username. These values can be used as part of the comment posting request in order to spoof the user.

Frequently asked questions

What is CVE-2021-33484?: An issue was discovered in CommentsService.ashx in OnyakTech Comments Pro 3.8. An attacker can download a copy of the installer, decompile it, and discover a hardcoded IV used to encrypt the username and userid in the comment POST request. Additionally, the attacker can decrypt the encrypted encryption key (sent as a parameter in the comment form request) by setting this encrypted value as the username, which will appear on the comment page in its decrypted form. Using these two values (combined with the encryption functionality discovered in the decompiled installer), the attacker can encrypt another user's ID and username. These values can be used as part of the comment posting request in order to spoof the user.
How severe is CVE-2021-33484?: CVE-2021-33484 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 high, integrity none, and availability none.
Is CVE-2021-33484 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33484?: CVE-2021-33484 affects Onyaktech Comments Pro Project Onyaktech Comments Pro. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33484?: 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-2021-33484 published?: CVE-2021-33484 was published on 2021-09-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:onyaktech_comments_pro_project:onyaktech_comments_pro:3.8:*:*:*:*:*:*:*

More vulnerabilities in Onyaktech Comments Pro Project Onyaktech Comments Pro

CVE-2021-33483 — Medium (CVSS 5.4): An issue was discovered in CommentsService.ashx in OnyakTech Comments Pro 3.8. The comment posting functionality allows…

All CVEs affecting Onyaktech Comments Pro Project Onyaktech Comments Pro →

Other CWE-798 (Use of Hard-coded Credentials) vulnerabilities

CVE-2026-13768 — Critical (CVSS 10.0): Gardyn devices expose a privileged iothubowner key. Access to this key will allow a malicious user to invoke an IoTHub…
CVE-2026-45631 — Critical (CVSS 10.0): Dokploy is a free, self-hostable Platform as a Service (PaaS). From 0.27.0 to before 0.29.3, a hardcoded…
CVE-2026-22769 — Critical (CVSS 10.0): Dell RecoverPoint for Virtual Machines, versions prior to 6.0.3.1 HF1, contain a hardcoded credential vulnerability.…
CVE-2025-42890 — Critical (CVSS 10.0): SQL Anywhere Monitor (Non-GUI) baked credentials into the code,exposing the resources or functionality to unintended…
CVE-2025-7503 — Critical (CVSS 10.0): An OEM IP camera manufactured by Shenzhen Liandian Communication Technology LTD exposes a Telnet service (port 23) with…
CVE-2025-20309 — Critical (CVSS 10.0): A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session…

Browse all CWE-798 (Use of Hard-coded Credentials) vulnerabilities →