Oracle ZFS Storage Appliance Kit 8.8 Operating System Image out-of-bounds write

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.6$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as very critical, was found in Oracle ZFS Storage Appliance Kit 8.8. This impacts an unknown function of the component Operating System Image. The manipulation results in an unknown weakness. This vulnerability is known as CVE-2021-26691. It is possible to launch the attack remotely. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Oracle ZFS Storage Appliance Kit 8.8. Affected is some unknown functionality of the component Operating System Image. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was published 10/19/2021 as Oracle Critical Patch Update Advisory - October 2021. The advisory is shared for download at oracle.com. This vulnerability is traded as CVE-2021-26691. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 01/21/2026).

As 0-day the estimated underground price was around $100k and more. The vulnerability scanner Nessus provides a plugin with the ID 294771 (MiracleLinux 8 : httpd:2.4 (AXSA:2021-2541:01)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (294771). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.6

VulDB Base Score: 9.8
VulDB Temp Score: 9.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 294771
Nessus Name: MiracleLinux 8 : httpd:2.4 (AXSA:2021-2541:01)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

02/04/2021 🔍
10/19/2021 +256 days 🔍
10/19/2021 +0 days 🔍
10/20/2021 +1 days 🔍
01/21/2026 +1554 days 🔍

Sourcesinfo

Vendor: oracle.com

Advisory: Oracle Critical Patch Update Advisory - October 2021
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-26691 (🔍)
GCVE (CVE): GCVE-0-2021-26691
GCVE (VulDB): GCVE-100-185040

Entryinfo

Created: 10/20/2021 08:11
Updated: 01/21/2026 11:20
Changes: 10/20/2021 08:11 (38), 10/27/2021 10:37 (3), 10/27/2021 10:42 (18), 01/21/2026 11:20 (16)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion

 Anonymous User (+0)
5 years ago
https://vuldb.com/?id.176768
These have the same CVE-number?
 VulDB Community Team5 years ago
A CVE is not unique in our database. We have a different splitting methodology than the CVE program.

◂ PreviousOverviewNext ▸

Want to stay up to date on a daily basis?

Enable the mail alert feature now!