CVE-2021-33484
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.89%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.89% probability · 59th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-798
- Affected
- onyaktech comments pro project/onyaktech comments pro
- Source
- cve@mitre.org
EPSS 0.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://burninatorsec.blogspot.com/2021/07/onyaktech-comments-pro-broken.htmlExploit, Third Party Advisory
- https://twitter.com/onyaktechThird Party Advisory
- https://burninatorsec.blogspot.com/2021/07/onyaktech-comments-pro-broken.htmlExploit, Third Party Advisory
- https://twitter.com/onyaktechThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.