high
7.4
CWE
755 703
Advisory Published
Updated

CVE-2021-0241: Junos OS: Receipt of specific DHCPv6 packet may cause jdhcpd to crash and restart

First published: Wed Apr 14 2021(Updated: )

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.

Credit: sirt@juniper.net

Affected SoftwareAffected VersionHow to fix
Juniper Junos=17.3
Juniper Junos=17.3-r1
Juniper Junos=17.3-r1-s1
Juniper Junos=17.3-r1-s4
Juniper Junos=17.3-r2
Juniper Junos=17.3-r2-s1
Juniper Junos=17.3-r2-s2
Juniper Junos=17.3-r2-s3
Juniper Junos=17.3-r2-s4
Juniper Junos=17.3-r2-s5
Juniper Junos=17.3-r3
Juniper Junos=17.3-r3
Juniper Junos=17.3-r3-s1
Juniper Junos=17.3-r3-s10
Juniper Junos=17.3-r3-s11
Juniper Junos=17.3-r3-s2
Juniper Junos=17.3-r3-s3
Juniper Junos=17.3-r3-s4
Juniper Junos=17.3-r3-s5
Juniper Junos=17.3-r3-s6
Juniper Junos=17.3-r3-s7
Juniper Junos=17.3-r3-s8
Juniper Junos=17.3-r3-s9
Juniper Junos=17.4
Juniper Junos=17.4-r1
Juniper Junos=17.4-r1-s1
Juniper Junos=17.4-r1-s2
Juniper Junos=17.4-r1-s3
Juniper Junos=17.4-r1-s4
Juniper Junos=17.4-r1-s5
Juniper Junos=17.4-r1-s6
Juniper Junos=17.4-r1-s7
Juniper Junos=17.4-r2
Juniper Junos=17.4-r2-s1
Juniper Junos=17.4-r2-s10
Juniper Junos=17.4-r2-s11
Juniper Junos=17.4-r2-s2
Juniper Junos=17.4-r2-s3
Juniper Junos=17.4-r2-s4
Juniper Junos=17.4-r2-s5
Juniper Junos=17.4-r2-s6
Juniper Junos=17.4-r2-s7
Juniper Junos=17.4-r2-s8
Juniper Junos=17.4-r2-s9
Juniper Junos=17.4-r3
Juniper Junos=17.4-r3-s1
Juniper Junos=17.4-r3-s2
Juniper Junos=17.4-r3-s3
Juniper Junos=17.4-r3-s4
Juniper Junos=18.1
Juniper Junos=18.1-r1
Juniper Junos=18.1-r2
Juniper Junos=18.1-r2-s1
Juniper Junos=18.1-r2-s2
Juniper Junos=18.1-r2-s4
Juniper Junos=18.1-r3
Juniper Junos=18.1-r3-s1
Juniper Junos=18.1-r3-s10
Juniper Junos=18.1-r3-s11
Juniper Junos=18.1-r3-s12
Juniper Junos=18.1-r3-s2
Juniper Junos=18.1-r3-s3
Juniper Junos=18.1-r3-s4
Juniper Junos=18.1-r3-s5
Juniper Junos=18.1-r3-s6
Juniper Junos=18.1-r3-s7
Juniper Junos=18.1-r3-s8
Juniper Junos=18.1-r3-s9
Juniper Junos=18.2
Juniper Junos=18.2-r1
Juniper Junos=18.2-r1
Juniper Junos=18.2-r1-s2
Juniper Junos=18.2-r1-s3
Juniper Junos=18.2-r1-s4
Juniper Junos=18.2-r1-s5
Juniper Junos=18.2-r2
Juniper Junos=18.2-r2-s1
Juniper Junos=18.2-r2-s2
Juniper Junos=18.2-r2-s3
Juniper Junos=18.2-r2-s4
Juniper Junos=18.2-r2-s5
Juniper Junos=18.2-r2-s6
Juniper Junos=18.2-r2-s7
Juniper Junos=18.2-r3
Juniper Junos=18.2-r3-s1
Juniper Junos=18.2-r3-s2
Juniper Junos=18.2-r3-s3
Juniper Junos=18.2-r3-s4
Juniper Junos=18.3
Juniper Junos=18.3-r1
Juniper Junos=18.3-r1-s1
Juniper Junos=18.3-r1-s2
Juniper Junos=18.3-r1-s3
Juniper Junos=18.3-r1-s4
Juniper Junos=18.3-r1-s5
Juniper Junos=18.3-r1-s6
Juniper Junos=18.3-r2
Juniper Junos=18.3-r2-s1
Juniper Junos=18.3-r2-s2
Juniper Junos=18.3-r2-s3
Juniper Junos=18.3-r2-s4
Juniper Junos=18.3-r3
Juniper Junos=18.3-r3-s1
Juniper Junos=18.3-r3-s2
Juniper Junos=18.3-r3-s3
Juniper Junos=18.3-r3-s4
Juniper Junos=18.4
Juniper Junos=18.4-r1
Juniper Junos=18.4-r1-s1
Juniper Junos=18.4-r1-s2
Juniper Junos=18.4-r1-s3
Juniper Junos=18.4-r1-s4
Juniper Junos=18.4-r1-s5
Juniper Junos=18.4-r1-s6
Juniper Junos=18.4-r1-s7
Juniper Junos=18.4-r2
Juniper Junos=18.4-r2-s1
Juniper Junos=18.4-r2-s2
Juniper Junos=18.4-r2-s3
Juniper Junos=18.4-r2-s4
Juniper Junos=18.4-r2-s5
Juniper Junos=18.4-r2-s6
Juniper Junos=18.4-r3
Juniper Junos=18.4-r3-s1
Juniper Junos=18.4-r3-s2
Juniper Junos=18.4-r3-s3
Juniper Junos=18.4-r3-s4
Juniper Junos=18.4-r3-s5
Juniper Junos=18.4-r3-s6
Juniper Junos=19.1
Juniper Junos=19.1-r1
Juniper Junos=19.1-r1-s1
Juniper Junos=19.1-r1-s2
Juniper Junos=19.1-r1-s3
Juniper Junos=19.1-r1-s4
Juniper Junos=19.1-r1-s5
Juniper Junos=19.1-r2
Juniper Junos=19.1-r2-s1
Juniper Junos=19.1-r3
Juniper Junos=19.1-r3-s1
Juniper Junos=19.1-r3-s2
Juniper Junos=19.1-r3-s3
Juniper Junos=19.1-r3-s4
Juniper Junos=19.2
Juniper Junos=19.2-r1
Juniper Junos=19.2-r1-s1
Juniper Junos=19.2-r1-s2
Juniper Junos=19.2-r1-s3
Juniper Junos=19.2-r1-s4
Juniper Junos=19.2-r1-s5
Juniper Junos=19.2-r2
Juniper Junos=19.2-r2-s1
Juniper Junos=19.2-r3
Juniper Junos=19.2-r3-s1
Juniper Junos=19.3
Juniper Junos=19.3-r1
Juniper Junos=19.3-r1-s1
Juniper Junos=19.3-r2
Juniper Junos=19.3-r2-s1
Juniper Junos=19.3-r2-s2
Juniper Junos=19.3-r2-s3
Juniper Junos=19.3-r2-s4
Juniper Junos=19.3-r2-s5
Juniper Junos=19.3-r3
Juniper Junos=19.4-r1
Juniper Junos=19.4-r1-s1
Juniper Junos=19.4-r1-s2
Juniper Junos=19.4-r2
Juniper Junos=19.4-r2-s1
Juniper Junos=19.4-r2-s2
Juniper Junos=19.4-r3
Juniper Junos=19.4-r3-s1
Juniper Junos=20.1-r1
Juniper Junos=20.1-r1-s1
Juniper Junos=20.1-r1-s2
Juniper Junos=20.1-r1-s3
Juniper Junos=20.1-r1-s4
Juniper Junos=20.1-r2
Juniper Junos=20.1-r2-s1
Juniper Junos=20.2-r1
Juniper Junos=20.2-r1-s1
Juniper Junos=20.2-r1-s2
Juniper Junos=20.2-r1-s3
Juniper Junos=20.2-r2
Juniper Junos=20.2-r2-s1
Juniper Junos=20.2-r2-s2
Juniper Junos=20.3-r1
Juniper Junos=20.3-r1-s1
Juniper Junos=20.4-r1

Remedy

The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S11, 17.4R3-S4, 18.1R3-S12, 18.2R3-S7, 18.3R3-S4, 18.4R3-S7, 19.1R3-S4, 19.2R3-S1, 19.3R3-S1, 19.3R3-S2, 19.4R3-S1, 20.1R2, 20.1R3, 20.2R2, 20.2R3, 20.3R1-S2, 20.3R2, 20.4R1, 21.1R1, and all subsequent releases.

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-0241?

    CVE-2021-0241 has been assigned a severity rating that indicates it can lead to potential denial of service due to crashes in the DHCPv6 daemon.

  • How can I mitigate CVE-2021-0241?

    To mitigate CVE-2021-0241, update your Juniper Junos OS to a version that addresses this vulnerability.

  • Which versions of Junos OS are affected by CVE-2021-0241?

    CVE-2021-0241 affects Junos OS versions including 17.3, 17.4, and 18.1, among others.

  • What symptoms indicate CVE-2021-0241 may be exploited?

    Symptoms of CVE-2021-0241 exploitation include unexpected crashes or restarts of the DHCPv6 daemon.

  • Is there a patch available for CVE-2021-0241?

    Yes, patches have been released for CVE-2021-0241 in the updated versions of Junos OS.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2025 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203