CVE-2021-0241

Junos OS: Receipt of specific DHCPv6 packet may cause jdhcpd to crash and restart

MEDIUM

6.5

CVSS Score

Published: April 22, 2021 at 07:37 PM UTC

Updated: June 17, 2026 at 03:29 AM UTC

1 product affected across 1 vendorJunos

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.4%

Description

On Juniper Networks Junos OS platforms configured as DHCPv6 local server or DHCPv6 Relay Agent, Juniper Networks Dynamic Host Configuration Protocol Daemon (JDHCPD) process might crash with a core dump if a specific DHCPv6 packet is received, resulting in a restart of the daemon. The daemon automatically restarts without intervention, but continued receipt and processing of these specific packets will repeatedly crash the JDHCPD process and sustain the Denial of Service (DoS) condition. This issue only affects DHCPv6. DHCPv4 is not affected by this issue. This issue affects: Juniper Networks Junos OS 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R3-S7; 19.1 versions prior to 19.1R3-S4; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R3-S1, 19.3R3-S2; 19.4 versions prior to 19.4R3-S1; 20.1 versions prior to 20.1R2, 20.1R3; 20.2 versions prior to 20.2R2, 20.2R3; 20.3 versions prior to 20.3R1-S2, 20.3R2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

17.3 ≤ v < 17.3R3-S1117.4 ≤ v < 17.4R3-S418.1 ≤ v < 18.1R3-S1218.2 ≤ v < 18.2R3-S718.3 ≤ v < 18.3R3-S418.4 ≤ v < 18.4R3-S719.1 ≤ v < 19.1R3-S419.2 ≤ v < 19.2R3-S119.3 ≤ v < 19.3R3-S1, 19.3R3-S219.4 ≤ v < 19.4R3-S120.1 ≤ v < 20.1R2, 20.1R320.2 ≤ v < 20.2R2, 20.2R320.3 ≤ v < 20.3R1-S2, 20.3R217.3 17.3 r1 17.3 r1-s1 17.3 r1-s4 17.3 r2 17.3 r2-s1 17.3 r2-s2 17.3 r2-s3 17.3 r2-s4 17.3 r2-s5 17.3 r3 17.3 r3-s1 17.3 r3-s10 17.3 r3-s11 17.3 r3-s2 17.3 r3-s3 17.3 r3-s4 17.3 r3-s5 17.3 r3-s6 17.3 r3-s7 17.3 r3-s8 17.3 r3-s9 17.4 17.4 r1 17.4 r1-s1 17.4 r1-s2 17.4 r1-s3 17.4 r1-s4 17.4 r1-s5 17.4 r1-s6 17.4 r1-s7 17.4 r2 17.4 r2-s1 17.4 r2-s10 17.4 r2-s11 17.4 r2-s2 17.4 r2-s3 17.4 r2-s4 17.4 r2-s5 17.4 r2-s6 17.4 r2-s7 17.4 r2-s8 17.4 r2-s9 17.4 r3 17.4 r3-s1 17.4 r3-s2 17.4 r3-s3 17.4 r3-s4 18.1 18.1 r1 18.1 r2 18.1 r2-s1 18.1 r2-s2 18.1 r2-s4 18.1 r3 18.1 r3-s1 18.1 r3-s10 18.1 r3-s11 18.1 r3-s12 18.1 r3-s2 18.1 r3-s3 18.1 r3-s4 18.1 r3-s5 18.1 r3-s6 18.1 r3-s7 18.1 r3-s8 18.1 r3-s9 18.2 18.2 r1 18.2 r1-s2 18.2 r1-s3 18.2 r1-s4 18.2 r1-s5 18.2 r2 18.2 r2-s1 18.2 r2-s2 18.2 r2-s3 18.2 r2-s4 18.2 r2-s5 18.2 r2-s6 18.2 r2-s7 18.2 r3 18.2 r3-s1 18.2 r3-s2 18.2 r3-s3 18.2 r3-s4 18.3 18.3 r1 18.3 r1-s1 18.3 r1-s2 18.3 r1-s3 18.3 r1-s4 18.3 r1-s5 18.3 r1-s6 18.3 r2 18.3 r2-s1 18.3 r2-s2 18.3 r2-s3 18.3 r2-s4 18.3 r3 18.3 r3-s1 18.3 r3-s2 18.3 r3-s3 18.3 r3-s4 18.4 18.4 r1 18.4 r1-s1 18.4 r1-s2 18.4 r1-s3 18.4 r1-s4 18.4 r1-s5 18.4 r1-s6 18.4 r1-s7 18.4 r2 18.4 r2-s1 18.4 r2-s2 18.4 r2-s3 18.4 r2-s4 18.4 r2-s5 18.4 r2-s6 18.4 r3 18.4 r3-s1 18.4 r3-s2 18.4 r3-s3 18.4 r3-s4 18.4 r3-s5 18.4 r3-s6 19.1 19.1 r1 19.1 r1-s1 19.1 r1-s2 19.1 r1-s3 19.1 r1-s4 19.1 r1-s5 19.1 r2 19.1 r2-s1 19.1 r3 19.1 r3-s1 19.1 r3-s2 19.1 r3-s3 19.1 r3-s4 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.2 r1-s4 19.2 r1-s5 19.2 r2 19.2 r2-s1 19.2 r3 19.2 r3-s1 19.3 19.3 r1 19.3 r1-s1 19.3 r2 19.3 r2-s1 19.3 r2-s2 19.3 r2-s3 19.3 r2-s4 19.3 r2-s5 19.3 r3 19.4 19.4 r1 19.4 r1-s1 19.4 r1-s2 19.4 r2 19.4 r2-s1 19.4 r2-s2 19.4 r3 19.4 r3-s1 20.1 20.1 r1 20.1 r1-s1 20.1 r1-s2 20.1 r1-s3 20.1 r1-s4 20.1 r2 20.1 r2-s1 20.2 20.2 r1 20.2 r1-s1 20.2 r1-s2 20.2 r1-s3 20.2 r2 20.2 r2-s1 20.2 r2-s2 20.3 20.3 r1 20.3 r1-s1 20.4 r1

Affected range stops below 17.3R3-S11, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.4R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.1R3-S12, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.3R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.4R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3R3-S1, 19.3R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.4R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.1R2, 20.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.2R2, 20.2R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.3R1-S2, 20.3R2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://kb.juniper.net/JSA11168

References (1)

x_refsource_MISCVendor Advisory

Source: [email protected]

https://kb.juniper.net/JSA11168

CVSS

6.5MEDIUM[email protected]

Attack Vector: ADJACENT_NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-703CWE-755

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