CVE-2021-33484: An issue was discovered in CommentsService.ashx in OnyakTech Comments Pro 3.8

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2021-33484 is a high-severity flaw (CVSS 7.5) affecting onyaktech comments pro. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 it

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 41%)
CISA exploited list	No
Weakness	CWE-798
Published	2021-09-07
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: onyaktech comments pro project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-09-07 05:15 UTCPublished CVE record published
2026-06-17 03:54 UTCUpdated Record last modified

onyaktech comments pro project onyaktech comments pro DOWNGRADE

Affected: 3.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.8

1. Check installed version

apt-cache policy onyaktech-comments-pro || rpm -q onyaktech-comments-pro || onyaktech-comments-pro --version

2. No fixed release: DOWNGRADE to a release before 3.8 (Debian / Ubuntu)

apt-cache madison onyaktech-comments-pro sudo apt install onyaktech-comments-pro=<VERSION_BEFORE_3.8> sudo apt-mark hold onyaktech-comments-pro

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list onyaktech-comments-pro sudo dnf downgrade onyaktech-comments-pro-<VERSION_BEFORE_3.8> sudo dnf versionlock add onyaktech-comments-pro

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-33484?

onyaktech comments pro: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-33484 being exploited?

CVE-2021-33484 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-33484 affect?

CVE-2021-33484 affects onyaktech comments pro. Severity is high (CVSS 7.5). 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.

How urgent is CVE-2021-33484?

Priority 51/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-33483 MEDIUM 5.4 DOWNGRADE An issue was discovered in CommentsService.ashx in OnyakTech Comments Pro 3.8

References

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