CVE-2015-5333Network attack vector

Remote memory exhaustion via ASN.1 OID leak

Published Jan 23, 2020 · Updated Aug 6, 2024

Memory leak in LibreSSL before 2.3.1 allows remote attackers to cause denial of service via large ASN.1 object identifier sets in X.509 certificates. OBJ_obj2txt allocates decimal strings for large subidentifiers but frees only the final temporary value, so repeated identifiers accumulate leaked memory during certificate decoding. The attack requires a service that processes attacker-supplied X.509 certificates; sufficient requests can exhaust process memory and interrupt service without granting data access or code execution.

CVSS severity7.5
High
EPSS probability1.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in LibreSSL before 2.3.1 allows remote attackers to cause denial of service via large ASN.1 object identifier sets in X.509 certificates. OBJ_obj2txt allocates decimal strings for large subidentifiers but frees only the final temporary value, so repeated identifiers accumulate leaked memory during certificate decoding. The attack requires a service that processes attacker-supplied X.509 certificates; sufficient requests can exhaust process memory and interrupt service without granting data access or code execution.

The record

CVE
CVE-2015-5333
Published
Jan 23, 2020
Updated
Aug 6, 2024
Vendor
OpenBSD Project
Product
LibreSSL
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=before 2.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenBSD Project · LibreSSLversion=before 2.3.1

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-400Uncontrolled Resource Consumption
T1499Network Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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