CVE-2020-1759

Message forgery via wrapped AES-GCM nonce counter

Published Apr 13, 2020 · Updated Aug 4, 2024

Nonce reuse in Ceph messenger v2 secure mode allows man-in-the-middle attackers to forge messages and disclose encrypted data. AES128GCM_OnWireTxHandler increments only a 32-bit nonce field, so it repeats after 2^32 frames while the 64-bit session continues. Exploitation requires an adjacent position and a long-lived secure-mode session whose counter wraps; consequences are limited to message disclosure and forgery.

CVSS severity6.4
Medium
EPSS probability1.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Nonce reuse in Ceph messenger v2 secure mode allows man-in-the-middle attackers to forge messages and disclose encrypted data. AES128GCM_OnWireTxHandler increments only a 32-bit nonce field, so it repeats after 2^32 frames while the 64-bit session continues. Exploitation requires an adjacent position and a long-lived secure-mode session whose counter wraps; consequences are limited to message disclosure and forgery.

The record

CVE
CVE-2020-1759
Published
Apr 13, 2020
Updated
Aug 4, 2024
Vendor
Ceph
Product
Ceph
Classifications
CWE-330, CWE-323, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

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  1. Affected versionversion=Red Hat Ceph Storage 4
  2. Affected versionversion=Red Hat Openshift Container Storage 4.2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Ceph · Cephversion=Red Hat Ceph Storage 4; version=Red Hat Openshift Container Storage 4.2

Published CVSS scores

6.4Red Hat, Inc.CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
6.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
5.8NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/A:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
CWE-323Reusing a Nonce, Key Pair in Encryption
T1557Adversary-in-the-Middle

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

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Your stack

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