CVE-2023-22415Network attack vector

Flowd crash via concurrent H.323 packet processing

Published Jan 12, 2023 · Updated Apr 7, 2025

Out-of-bounds write in the Junos OS H.323 ALG allows remote attackers to crash flowd with simultaneous crafted H.323 packets. The ALG mishandles specific concurrent H.323 packets and writes beyond a buffer boundary, terminating the flow processing daemon. H.323 ALG must be enabled, as it is by default; continued packet delivery repeatedly crashes flowd and sustains the service interruption on affected MX and SRX devices.

CVSS severity7.5
High
EPSS probability0.78%
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 the Junos OS H.323 ALG allows remote attackers to crash flowd with simultaneous crafted H.323 packets. The ALG mishandles specific concurrent H.323 packets and writes beyond a buffer boundary, terminating the flow processing daemon. H.323 ALG must be enabled, as it is by default; continued packet delivery repeatedly crashes flowd and sustains the service interruption on affected MX and SRX devices.

The record

CVE
CVE-2023-22415
Published
Jan 12, 2023
Updated
Apr 7, 2025
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-787, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 2025Record 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?

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

  1. Affected versionversion=20.2 <20.2R3-S6
  2. Affected versionversion=20.3 <20.3R3-S6
  3. Affected versionversion=20.4 <20.4R3-S5
  4. Affected versionversion=21.1 <21.1R3-S4
  5. Affected versionversion=21.2 <21.2R3-S3
  6. Affected versionversion=21.3 <21.3R3-S3
  7. Affected versionversion=21.4 <21.4R3
  8. Affected versionversion=22.1 <22.1R2-S1, 22.1R3
  9. Affected versionversion=22.2 <22.2R1-S2, 22.2R2
  10. Affected versionversion=unspecified <19.4R3-S10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Juniper Networks · Junos OSversion=20.2 <20.2R3-S6; version=20.3 <20.3R3-S6; version=20.4 <20.4R3-S5; version=21.1 <21.1R3-S4; version=21.2 <21.2R3-S3; version=21.3 <21.3R3-S3; version=21.4 <21.4R3; version=22.1 <22.1R2-S1, 22.1R3; version=22.2 <22.2R1-S2, 22.2R2; version=unspecified <19.4R3-S10

Published CVSS scores

7.5Juniper NetworksCVSS: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

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-787Out-of-bounds Write
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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