What is CVE-2021-33035?A high-severity flaw in Openoffice, explained.
CVE-2021-33035 is a high-severity flaw (CVSS 7.8) in Openoffice from Apache, published on 23 September 2021. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 51%. If you run an affected version, plan in the vendor’s fix.
Published 23 September 2021. Record last updated 7 November 2023. We keep this page's data up to date.
What is CVE-2021-33035? In plain terms.
An attacker has to be already on the device without logging in, but a person has to take an action first. If it works, the attacker can read data, change data and take it offline.
Apache OpenOffice opens dBase/DBF documents and shows the contents as spreadsheets. DBF are database files with data organized in fields. When reading DBF data the size of certain fields is not checked: the data is just copied into local variables. A carefully crafted document could overflow the allocated space, leading to the execution of arbitrary code by altering the contents of the program stack. This issue affects Apache OpenOffice up to and including version 4.1.10
What kind of flaw is it?
- CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAlready on the device
- How hard it is to pull offEasy: no special conditions
- Login needed firstNo login needed
- Does someone have to clickYes, a person has to take an action
- What an attacker getsCan read data, change data and take it offline
Severity vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Is CVE-2021-33035 being exploited? Not that we know of.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 51%. That can change at any time, which is why we keep watching.
Timeline
- Published
- Record last updated
- Exploit likelihood jumped
CVE-2021-33035 scores 43. Action: Plan remediation.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isSmaller factor
- Threat activity around itSmaller factor
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2021-33035 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2021-33035? One product.
The published record lists 1 product from 1 vendor. If you run one of these, check your version, then go to the fix below.
- Application
Openoffice
by Apache
Affected versionsup to 4.1.10
How do I fix CVE-2021-33035? Four steps.
- Check whether you run itCompare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
- Apply the vendor’s fixInstall the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Keep an eye on itTrack the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.
References
4 links- oss-security mailing list post, 7 Oct 2021 (opens in a new tab)openwall.com · 2021
- apache/openoffice commit (opens in a new tab)github.com
- R1ab8532e11f41bc7ca057ac7e39cab25f2e1f9d5f4929788ae21c8b9@<users.openoffice.apache.org> (opens in a new tab)apache.org
- R929c0c6a53cad64a1007b878342756badbb05ddd9b8f31a6d0b424cb@<announce.apache.org> (opens in a new tab)apache.org
Does CVE-2021-33035 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
Free plan, no card needed. Nothing to install.
1 new flaw affects software Acme tracks
Apache OpenOffice opens dBase/DBF documents and shows the contents as spreadsheets. DBF are database files with data organized in fields. When reading DBF da...
- Matched to
- Openoffice on Acme's software list
- What to do
- Plan in the vendor’s update
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2021-33035 is a high-severity flaw in Openoffice from Apache, published on 23 September 2021. An attacker has to be already on the device without logging in, but a person has to take an action first. If it works, the attacker can read data, change data and take it offline.
It scores 7.8 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2021-33035 is 43 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 51%. That can change at any time, which is why we keep watching.
For Openoffice from Apache: up to 4.1.10.
Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.