Sign inStart freeBook a demo

What is CVE-2023-0215?A high-severity flaw in OpenSSL, explained.

High severity2 affected products
The short answer

CVE-2023-0215 is a high-severity flaw (CVSS 7.5) in OpenSSL, published on 8 February 2023. 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 5.0%. If you run an affected version, plan in the vendor’s fix.

Check if it affects you →How to fix it

Published 8 February 2023. Record last updated 4 November 2025. We keep this page's data up to date.

What it does

What is CVE-2023-0215? In plain terms.

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline.

The official description

The public API function BIO_new_NDEF is a helper function used for streaming ASN.1 data via a BIO. It is primarily used internally to OpenSSL to support the SMIME, CMS and PKCS7 streaming capabilities, but may also be called directly by end user applications.

The function receives a BIO from the caller, prepends a new BIO_f_asn1 filter BIO onto the front of it to form a BIO chain, and then returns the new head of the BIO chain to the caller. Under certain conditions, for example if a CMS recipient public key is invalid, the new filter BIO is freed and the function returns a NULL result indicating a failure. However, in this case, the BIO chain is not properly cleaned up and the BIO passed by the caller still retains internal pointers to the previously freed filter BIO. If the caller then goes on to call BIO_pop() on the BIO then a use-after-free will occur. This will most likely result in a crash.

This scenario occurs directly in the internal function B64_write_ASN1() which may cause BIO_new_NDEF() to be called and will subsequently call BIO_pop() on the BIO. This internal function is in turn called by the public API functions PEM_write_bio_ASN1_stream, PEM_write_bio_CMS_stream, PEM_write_bio_PKCS7_stream, SMIME_write_ASN1, SMIME_write_CMS and SMIME_write_PKCS7.

Other public API functions that may be impacted by this include i2d_ASN1_bio_stream, BIO_new_CMS, BIO_new_PKCS7, i2d_CMS_bio_stream and i2d_PKCS7_bio_stream.

The OpenSSL cms and smime command line applications are similarly affected.

What kind of flaw is it?

  • CWE-416Use After Free
CVSS 3.1 scoreHigh · 7.5

How an attack on it works

Read straight from its severity rating, translated out of the shorthand.

  • Where an attacker can beAnywhere on the internet
  • How hard it is to pull offEasy: no special conditions
  • Login needed firstNo login needed
  • Does someone have to clickNo, nobody has to do anything
  • What an attacker getsCan take it offline

Severity vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation

Is CVE-2023-0215 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 5.0%. That can change at any time, which is why we keep watching.

Known to be exploitedNoNot on the list of exploited flaws today
Chance of use in the next 30 days5.0%Its EPSS score, from the latest forecast

Timeline

  1. Published
  2. Record last updated
  3. Exploit likelihood jumped
  4. Exploit likelihood fell
How Precursor Intelligence ranks it
49out of 100Medium

CVE-2023-0215 scores 49. 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-2023-0215 matches software you track, it lands in your list with its score and the reasons behind it.

See your own ranked list →
Affected products

Who is affected by CVE-2023-0215? 2 products.

The published record lists 2 products from 2 vendors. Versions are shown as published: "1.0.2 to before 1.0.2zg" means from 1.0.2 up to, but not including, 1.0.2zg. If you run one of these, check your version, then go to the fix below.

Remediation

How do I fix CVE-2023-0215? Four steps.

  1. 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.
  2. 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.
  3. 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.
  4. 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

9 links
Precursor Intelligence

Does CVE-2023-0215 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.

  1. Tell us what you runPick your software from a list, or let us work it out from your website.
  2. We match it to every flawOver 400,000 published flaws, checked against your list.
  3. Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
  4. Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
Start free →Book a demo

Free plan, no card needed. Nothing to install.

FAQ

Common questions, answered plainly.

Something else? Talk to the team →

CVE-2023-0215 is a high-severity flaw in OpenSSL, published on 8 February 2023. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can take it offline.

It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2023-0215 is 49 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

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 5.0%. That can change at any time, which is why we keep watching.

For OpenSSL: 1.0.2 to before 1.0.2zg, 1.1.1 to before 1.1.1t, 3.0.0 to before 3.0.8. The record lists 2 products in all, each with its versions, under "Who is affected" on this page.

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.

Keep exploring