CVE-2020-1661

Junos OS: jdhcpd process crash when forwarding a malformed DHCP packet.

MEDIUM

5.3

CVSS Score

Published: October 16, 2020 at 08:31 PM UTC

Updated: June 17, 2026 at 03:02 AM UTC

32 products affected across 2 vendorsJunosSRX5600SRX5800

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Severity

MEDIUM5.3

Exploit prediction

EPSS 1.0%

Description

On Juniper Networks Junos OS devices configured as a DHCP forwarder, the Juniper Networks Dynamic Host Configuration Protocol Daemon (jdhcp) process might crash when receiving a malformed DHCP packet. This issue only affects devices configured as DHCP forwarder with forward-only option, that forward specified DHCP client packets, without creating a new subscriber session. The jdhcpd daemon automatically restarts without intervention, but continuous receipt of the malformed DHCP packet will repeatedly crash jdhcpd, leading to an extended Denial of Service (DoS) condition. This issue can be triggered only by DHCPv4, it cannot be triggered by DHCPv6. This issue affects Juniper Networks Junos OS: 12.3 versions prior to 12.3R12-S16; 12.3X48 versions prior to 12.3X48-D105 on SRX Series; 14.1X53 versions prior to 14.1X53-D60 on EX and QFX Series; 15.1 versions prior to 15.1R7-S7; 15.1X49 versions prior to 15.1X49-D221, 15.1X49-D230 on SRX Series; 15.1X53 versions prior to 15.1X53-D593 on EX2300/EX3400; 16.1 versions prior to 16.1R7-S5.

Affected

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

Junos · Juniper Networks

95%

12.3 ≤ v < 12.3R12-S1612.3X48 ≤ v < 12.3X48-D10514.1X53 ≤ v < 14.1X53-D6015.1 ≤ v < 15.1R7-S715.1X49 ≤ v < 15.1X49-D221, 15.1X49-D23015.1X53 ≤ v < 15.1X53-D59316.1 ≤ v < 16.1R7-S512.3 12.3 r1 12.3 r10 12.3 r10-s1 12.3 r10-s2 12.3 r11 12.3 r12 12.3 r12-s1 12.3 r12-s11 12.3 r12-s12 12.3 r12-s13 12.3 r12-s14 12.3 r12-s15 12.3 r12-s3 12.3 r12-s4 12.3 r12-s6 12.3 r12-s8 12.3 r2 12.3 r3 12.3 r4 12.3 r5 12.3 r6 12.3 r7 12.3 r8 12.3 r9 12.3X4812.3x4812.3x48 d10 12.3x48 d100 12.3x48 d15 12.3x48 d20 12.3x48 d25 12.3x48 d30 12.3x48 d35 12.3x48 d40 12.3x48 d45 12.3x48 d50 12.3x48 d51 12.3x48 d55 12.3x48 d60 12.3x48 d65 12.3x48 d70 12.3x48 d7512.3x48 d8012.3x48 d90 12.3x48 d95 14.1X5314.1x5314.1x53 d10 14.1x53 d15 14.1x53 d16 14.1x53 d25 14.1x53 d26 14.1x53 d27 14.1x53 d30 14.1x53 d34 14.1x53 d35 14.1x53 d40 14.1x53 d42 14.1x53 d43 14.1x53 d44 14.1x53 d45 14.1x53 d48 14.1x53 d50 14.1x53 d51 14.1x53 d52 14.1x53 d53 15.1 15.1 a1 15.1 f 15.1 f1 15.1 f2 15.1 f2-s1 15.1 f2-s2 15.1 f2-s3 15.1 f2-s4 15.1 f3 15.1 f4 15.1 f5 15.1 f5-s7 15.1 f6 15.1 f6-s1 15.1 f6-s12 15.1 f6-s2 15.1 f6-s3 15.1 f6-s4 15.1 f6-s7 15.1 f7 15.1 r1 15.1 r2 15.1 r3 15.1 r4 15.1 r4-s7 15.1 r4-s8 15.1 r4-s9 15.1 r5 15.1 r5-s1 15.1 r5-s5 15.1 r5-s6 15.1 r6 15.1 r6-s1 15.1 r6-s2 15.1 r6-s6 15.1 r7 15.1 r7-s1 15.1 r7-s2 15.1 r7-s3 15.1 r7-s4 15.1 r7-s5 15.1 r7-s6 15.1X49 15.1X5315.1x4915.1x49 d10 15.1x49 d100 15.1x49 d110 15.1x49 d120 15.1x49 d130 15.1x49 d140 15.1x49 d15 15.1x49 d150 15.1x49 d160 15.1x49 d170 15.1x49 d180 15.1x49 d190 15.1x49 d20 15.1x49 d200 15.1x49 d210 15.1x49 d25 15.1x49 d30 15.1x49 d35 15.1x49 d40 15.1x49 d45 15.1x49 d50 15.1x49 d55 15.1x49 d60 15.1x49 d65 15.1x49 d70 15.1x49 d75 15.1x49 d80 15.1x49 d9015.1x5315.1x53 d10 15.1x53 d20 15.1x53 d21 15.1x53 d210 15.1x53 d230 15.1x53 d231 15.1x53 d23215.1x53 d23315.1x53 d234 15.1x53 d235 15.1x53 d236 15.1x53 d237 15.1x53 d25 15.1x53 d30 15.1x53 d31 15.1x53 d32 15.1x53 d33 15.1x53 d34 15.1x53 d40 15.1x53 d45 15.1x53 d47 15.1x53 d470 15.1x53 d48 15.1x53 d495 15.1x53 d50 15.1x53 d51 15.1x53 d52 15.1x53 d55 15.1x53 d56 15.1x53 d57 15.1x53 d5815.1x53 d5915.1x53 d590 15.1x53 d591 15.1x53 d592 15.1x53 d60 15.1x53 d61 15.1x53 d62 15.1x53 d63 15.1x53 d64 15.1x53 d65 15.1x53 d6615.1x53 d6715.1x53 d68 15.1x53 d69 15.1x53 d70 16.1 16.1 r1 16.1 r2 16.1 r3 16.1 r3-s10 16.1 r3-s11 16.1 r4 16.1 r4-s12 16.1 r4-s2 16.1 r4-s3 16.1 r4-s4 16.1 r4-s6 16.1 r5 16.1 r5-s4 16.1 r6-s1 16.1 r6-s6 16.1 r7 16.1 r7-s2 16.1 r7-s3 16.1 r7-s4

Affected range stops below 12.3R12-S16, so it looks safe — our inference, not a vendor statement

Affected range stops below 12.3X48-D105, so it looks safe — our inference, not a vendor statement

Affected range stops below 14.1X53-D60, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1R7-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X49-D221, 15.1X49-D230, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X53-D593, so it looks safe — our inference, not a vendor statement

Affected range stops below 16.1R7-S5, so it looks safe — our inference, not a vendor statement

juniper-ex2300 (environment) · juniper-ex2300-c (environment) · juniper-ex3400 (environment) · juniper-ex4300 (environment) · juniper-ex4600 (environment) · juniper-ex4650 (environment) · juniper-ex9200 (environment) · juniper-ex9250 (environment) · juniper-qfx10002 (environment) · juniper-qfx10008 (environment) · juniper-qfx10016 (environment) · juniper-qfx5100 (environment) · juniper-qfx5110 (environment) · juniper-qfx5120 (environment) · juniper-qfx5130 (environment) · juniper-qfx5200 (environment) · juniper-qfx5210 (environment) · juniper-qfx5220 (environment) · juniper-srx1500 (environment) · juniper-srx300 (environment) · juniper-srx320 (environment) · juniper-srx340 (environment) · juniper-srx345 (environment) · juniper-srx380 (environment) · juniper-srx4100 (environment) · juniper-srx4200 (environment) · juniper-srx4600 (environment) · juniper-srx5400 (environment) · juniper-srx550 (environment) · juniper-srx5600 (environment) · juniper-srx5800 (environment)

Ex2300 · Juniperdevice

80%

All versions

Ex2300-C · Juniperdevice

80%

All versions

Ex3400 · Juniperdevice

80%

All versions

Ex4300 · Juniperdevice

80%

All versions