CVE-2023-36660Network attack vector

Memory corruption via reversed OCB buffer advance

Published Jun 25, 2023 · Updated Aug 2, 2024

Out-of-bounds write in Nettle 3.9's OCB implementation allows remote attackers to corrupt memory with a sufficiently large message. In ocb_crypt_n, the multi-block loop advances the source pointer but subtracts the processed size from the destination pointer, so later iterations write before the output buffer. Triggering requires an application to pass attacker-controlled data large enough to repeat that OCB loop, resulting in a crash or other process corruption.

CVSS severity9.8
Critical
EPSS probability1.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Nettle 3.9's OCB implementation allows remote attackers to corrupt memory with a sufficiently large message. In ocb_crypt_n, the multi-block loop advances the source pointer but subtracts the processed size from the destination pointer, so later iterations write before the output buffer. Triggering requires an application to pass attacker-controlled data large enough to repeat that OCB loop, resulting in a crash or other process corruption.

The record

CVE
CVE-2023-36660
Published
Jun 25, 2023
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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?

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

6.1SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.3Amazon LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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