CVE-2023-35784Network attack vector

Process memory corruption via dangling verified-chain pointer

Published Jun 16, 2023 · Updated Dec 17, 2024

Memory corruption in LibreSSL before 3.6.3 and 3.7.x before 3.7.3 allows remote attackers to trigger a double free after SSL_clear. The ssl3_free routine frees the verified peer-certificate chain but leaves its pointer valid, so later SSL object reuse can free or access the released chain again. Reachability requires an application to call SSL_clear on a connection object after peer verification; affected OpenBSD releases can experience process corruption or a crash.

CVSS severity9.8
Critical
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Memory corruption in LibreSSL before 3.6.3 and 3.7.x before 3.7.3 allows remote attackers to trigger a double free after SSL_clear. The ssl3_free routine frees the verified peer-certificate chain but leaves its pointer valid, so later SSL object reuse can free or access the released chain again. Reachability requires an application to call SSL_clear on a connection object after peer verification; affected OpenBSD releases can experience process corruption or a crash.

The record

CVE
CVE-2023-35784
Published
Jun 16, 2023
Updated
Dec 17, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, CWE-415
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 16, 2023CVE publishedPublication date reported by the CVE source.
  2. Dec 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
CWE-415Double Free

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo