CyberSecBulletin
CVE-2024-39516NVD status: Analyzed

Junos OS: Out-of-bounds Read

CVE-2024-39516 is a high-severity out-of-bounds read vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 21.4R3-S8, 22.2R3-S5, 22.3R3-S4 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Junos OS to 21.4R3-S8 or 22.2R3-S5 or 22.3R3-S4 or 22.4R3-S3, whichever matches your release line, or a later version.
  2. Update Junos OS Evolved to 21.4R3-S8-EVO or 22.2R3-S5-EVO or 22.3R3-S4-EVO or 22.4R3-S3-EVO, whichever matches your release line, or a later version.
  3. Update junos to 21.4R3-S8 or 22.2R3-S5 or 22.3R3-S4 or 22.4R3-S3, whichever matches your release line, or a later version.
  4. Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Juniper NetworksJunos OSbefore 21.4R3-S8; 22.2 up to, but not including, 22.2R3-S5; 22.3 up to, but not including, 22.3R3-S4; 22.4 up to, but not including, 22.4R3-S3; 23.2 up to, but not including, 23.2R2-S2; 23.4 up to, but not including, 23.4R221.4R3-S8, 22.2R3-S5, 22.3R3-S4, 22.4R3-S3, 23.2R2-S2, 23.4R2
Juniper NetworksJunos OS Evolvedbefore 21.4R3-S8-EVO; 22.2-EVO up to, but not including, 22.2R3-S5-EVO; 22.3-EVO up to, but not including, 22.3R3-S4-EVO; 22.4-EVO up to, but not including, 22.4R3-S3-EVO; 23.2-EVO up to, but not including, 23.2R2-S2-EVO; 23.4-EVO up to, but not including, 23.4R2-EVO; before 21.4R3-S8; 22.2 up to, but not including, 22.2R3-S5; and 4 more ranges21.4R3-S8-EVO, 22.2R3-S5-EVO, 22.3R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S2-EVO, 23.4R2-EVO
Juniper Networksjunosbefore 21.4R3-S8; 22.2 up to, but not including, 22.2R3-S5; 22.3 up to, but not including, 22.3R3-S4; 22.4 up to, but not including, 22.4R3-S3; 23.2 up to, but not including, 23.2R2-S2; 23.4 up to, but not including, 23.4R221.4R3-S8, 22.2R3-S5, 22.3R3-S4, 22.4R3-S3, 23.2R2-S2, 23.4R2

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (juniper.net).

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (juniper.net)
CVSS 3.17.5HighCNA (juniper.net)

Official description

An Out-of-Bounds Read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects systems configured in either of two ways: * systems with BGP traceoptions enabled * systems with BGP traffic engineering configured This issue can affect iBGP and eBGP with any address family configured. The specific attribute involved is non-transitive, and will not propagate across a network. This issue affects: Junos OS: * All versions before 21.4R3-S8, * 22.2 before 22.2R3-S5, * 22.3 before 22.3R3-S4, * 22.4 before 22.4R3-S3, * 23.2 before 23.2R2-S2, * 23.4 before 23.4R2; Junos OS Evolved: * All versions before 21.4R3-S8-EVO, * 22.2-EVO before 22.2R3-S5-EVO, * 22.3-EVO before 22.3R3-S4-EVO, * 22.4-EVO before 22.4R3-S3-EVO, * 23.2-EVO before 23.2R2-S2-EVO, * 23.4-EVO before 23.4R2-EVO.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Junos OS

All Junos OS vulnerabilities

Recent Out-of-bounds Read vulnerabilities

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