CVE-2019-20427Network attack vector

Server panic via signed packet-size handling

Published Jan 27, 2020 · Updated Aug 5, 2024

Buffer overflow in Lustre before 2.12.3 allows remote attackers to panic a server through crafted client packets. The ptlrpc request path accepts a client-controlled size from req_capsule_get_size, and tgt_brw_write uses it despite a signedness error in tgt_shortio2pages that permits an oversized buffer operation. Network access as a Lustre client is sufficient; the confirmed outcome is a server panic, while remote code execution remains reported but unconfirmed.

CVSS severity9.8
Critical
EPSS probability4.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Lustre before 2.12.3 allows remote attackers to panic a server through crafted client packets. The ptlrpc request path accepts a client-controlled size from req_capsule_get_size, and tgt_brw_write uses it despite a signedness error in tgt_shortio2pages that permits an oversized buffer operation. Network access as a Lustre client is sufficient; the confirmed outcome is a server panic, while remote code execution remains reported but unconfirmed.

The record

CVE
CVE-2019-20427
Published
Jan 27, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 27, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.0NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:C

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 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-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499Endpoint Denial of Service

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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