CVE-2021-0290
Junos OS: MX Series, EX9200 Series, SRX4600: Ethernet interface vulnerable to specially crafted frames
Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper Networks Junos OS allows an attacker to send specially crafted frames over the local Ethernet segment, causing the interface to go into a down state, resulting in a Denial of Service (DoS) condition. The interface does not recover on its own and the FPC must be reset manually. Continued receipt and processing of these frames will create a sustained Denial of Service (DoS) condition. This issue is platform-specific and affects the following platforms and line cards: * MPC7E/8E/9E and MPC10E on MX240, MX480, MX960, MX2008, MX2010, and MX2020 * MX204, MX10003, MX10008, MX10016 * EX9200, EX9251 * SRX4600 No other products or platforms are affected by this vulnerability. An indication of this issue occurring can be seen in the system log messages, as shown below: user@host> show log messages | match "Failed to complete DFE tuning" fpc4 smic_phy_dfe_tuning_state: et-4/1/6 - Failed to complete DFE tuning (count 3) and interface will be in a permanently down state: user@host> show interfaces et-4/1/6 terse Interface Admin Link Proto Local Remote et-4/1/6 up down et-4/1/6.0 up down aenet --> ae101.0 This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S7 on MX Series; 17.1R1 and later versions prior to 17.2R3-S3 on MX Series; 17.3 versions prior to 17.3R3-S8 on MX Series; 17.4 versions prior to 17.4R2-S11, 17.4R3-S1 on MX Series, SRX4600; 18.1 versions prior to 18.1R3-S10 on MX Series, EX9200 Series, SRX4600; 18.2 versions prior to 18.2R3-S3 on MX Series, EX9200 Series, SRX4600; 18.3 versions prior to 18.3R3-S1 on MX Series, EX9200 Series, SRX4600; 18.4 versions prior to 18.4R2-S3, 18.4R3 on MX Series, EX9200 Series, SRX4600; 19.1 versions prior to 19.1R2-S1, 19.1R3 on MX Series, EX9200 Series, SRX4600; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series, EX9200 Series, SRX4600; 19.3 versions prior to 19.3R2 on MX Series, EX9200 Series, SRX4600. This issue does not affect Juniper Networks Junos OS versions prior to 16.1R1.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
6.5
Junos OS: MX Series, EX9200 Series, SRX4600: Ethernet interface vulnerable to specially crafted frames
Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper Networks Junos OS allows an attacker to send specially crafted frames over the local Ethernet segment, causing the interface to go into a down state, resulting in a Denial of Service (DoS) condition. The interface does not recover on its own and the FPC must be reset manually. Continued receipt and processing of these frames will create a sustained Denial of Service (DoS) condition. This issue is platform-specific and affects the following platforms and line cards: * MPC7E/8E/9E and MPC10E on MX240, MX480, MX960, MX2008, MX2010, and MX2020 * MX204, MX10003, MX10008, MX10016 * EX9200, EX9251 * SRX4600 No other products or platforms are affected by this vulnerability. An indication of this issue occurring can be seen in the system log messages, as shown below: user@host> show log messages | match "Failed to complete DFE tuning" fpc4 smic_phy_dfe_tuning_state: et-4/1/6 - Failed to complete DFE tuning (count 3) and interface will be in a permanently down state: user@host> show interfaces et-4/1/6 terse Interface Admin Link Proto Local Remote et-4/1/6 up down et-4/1/6.0 up down aenet --> ae101.0 This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S7 on MX Series; 17.1R1 and later versions prior to 17.2R3-S3 on MX Series; 17.3 versions prior to 17.3R3-S8 on MX Series; 17.4 versions prior to 17.4R2-S11, 17.4R3-S1 on MX Series, SRX4600; 18.1 versions prior to 18.1R3-S10 on MX Series, EX9200 Series, SRX4600; 18.2 versions prior to 18.2R3-S3 on MX Series, EX9200 Series, SRX4600; 18.3 versions prior to 18.3R3-S1 on MX Series, EX9200 Series, SRX4600; 18.4 versions prior to 18.4R2-S3, 18.4R3 on MX Series, EX9200 Series, SRX4600; 19.1 versions prior to 19.1R2-S1, 19.1R3 on MX Series, EX9200 Series, SRX4600; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series, EX9200 Series, SRX4600; 19.3 versions prior to 19.3R2 on MX Series, EX9200 Series, SRX4600. This issue does not affect Juniper Networks Junos OS versions prior to 16.1R1.
- Record
CVE-2021-0290- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-755
- Updated
- 2026-11-02
EUVDEUVD-2021-2909
6.5
Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper Networks Junos OS allows an attacker to send specially crafted frames over the local Ethernet segment, causing the interface to go into a down state, resulting in a Denial of Service (DoS) condition. The interface does not recover on its own and the FPC must be reset manually. Continued receipt and processing of these frames will create a sustained Denial of Service (DoS) condition. This issue is platform-specific and affects the following platforms and line cards: * MPC7E/8E/9E and MPC10E on MX240, MX480, MX960, MX2008, MX2010, and MX2020 * MX204, MX10003, MX10008, MX10016 * EX9200, EX9251 * SRX4600 No other products or platforms are affected by this vulnerability. An indication of this issue occurring can be seen in the system log messages, as shown below: user@host> show log messages | match "Failed to complete DFE tuning" fpc4 smic_phy_dfe_tuning_state: et-4/1/6 - Failed to complete DFE tuning (count 3) and interface will be in a permanently down state: user@host> show interfaces et-4/1/6 terse Interface Admin Link Proto Local Remote et-4/1/6 up down et-4/1/6.0 up down aenet --> ae101.0 This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S7 on MX Series; 17.1R1 and later versions prior to 17.2R3-S3 on MX Series; 17.3 versions prior to 17.3R3-S8 on MX Series; 17.4 versions prior to 17.4R2-S11, 17.4R3-S1 on MX Series, SRX4600; 18.1 versions prior to 18.1R3-S10 on MX Series, EX9200 Series, SRX4600; 18.2 versions prior to 18.2R3-S3 on MX Series, EX9200 Series, SRX4600; 18.3 versions prior to 18.3R3-S1 on MX Series, EX9200 Series, SRX4600; 18.4 versions prior to 18.4R2-S3, 18.4R3 on MX Series, EX9200 Series, SRX4600; 19.1 versions prior to 19.1R2-S1, 19.1R3 on MX Series, EX9200 Series, SRX4600; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series, EX9200 Series, SRX4600; 19.3 versions prior to 19.3R2 on MX Series, EX9200 Series, SRX4600. This issue does not affect Juniper Networks Junos OS versions prior to 16.1R1.
- Record
EUVD-2021-2909- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j4m5-242v-49g4 No score
Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper...
Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper Networks Junos OS allows an attacker to send specially crafted frames over the local Ethernet segment, causing the interface to go into a down state, resulting in a Denial of Service (DoS) condition. The interface does not recover on its own and the FPC must be reset manually. Continued receipt and processing of these frames will create a sustained Denial of Service (DoS) condition. This issue is platform-specific and affects the following platforms and line cards: * MPC7E/8E/9E and MPC10E on MX240, MX480, MX960, MX2008, MX2010, and MX2020 * MX204, MX10003, MX10008, MX10016 * EX9200, EX9251 * SRX4600 No other products or platforms are affected by this vulnerability. An indication of this issue occurring can be seen in the system log messages, as shown below: user@host> show log messages | match "Failed to complete DFE tuning" fpc4 smic_phy_dfe_tuning_state: et-4/1/6 - Failed to complete DFE tuning (count 3) and interface will be in a permanently down state: user@host> show interfaces et-4/1/6 terse Interface Admin Link Proto Local Remote et-4/1/6 up down et-4/1/6.0 up down aenet --> ae101.0 This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S7 on MX Series; 17.1R1 and later versions prior to 17.2R3-S3 on MX Series; 17.3 versions prior to 17.3R3-S8 on MX Series; 17.4 versions prior to 17.4R2-S11, 17.4R3-S1 on MX Series, SRX4600; 18.1 versions prior to 18.1R3-S10 on MX Series, EX9200 Series, SRX4600; 18.2 versions prior to 18.2R3-S3 on MX Series, EX9200 Series, SRX4600; 18.3 versions prior to 18.3R3-S1 on MX Series, EX9200 Series, SRX4600; 18.4 versions prior to 18.4R2-S3, 18.4R3 on MX Series, EX9200 Series, SRX4600; 19.1 versions prior to 19.1R2-S1, 19.1R3 on MX Series, EX9200 Series, SRX4600; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series, EX9200 Series, SRX4600; 19.3 versions prior to 19.3R2 on MX Series, EX9200 Series, SRX4600. This issue does not affect Juniper Networks Junos OS versions prior to 16.1R1.
- Record
GHSA-j4m5-242v-49g4- Weakness
- CWE-755
- Updated
- 2026-11-02
NVD
6.5
Improper Handling of Exceptional Conditions in Ethernet interface frame processing of Juniper Networks Junos OS allows an attacker to send specially crafted frames over the local Ethernet segment, causing the interface to go into a down state, resulting in a Denial of Service (DoS) condition. The interface does not recover on its own and the FPC must be reset manually. Continued receipt and processing of these frames will create a sustained Denial of Service (DoS) condition. This issue is platform-specific and affects the following platforms and line cards: * MPC7E/8E/9E and MPC10E on MX240, MX480, MX960, MX2008, MX2010, and MX2020 * MX204, MX10003, MX10008, MX10016 * EX9200, EX9251 * SRX4600 No other products or platforms are affected by this vulnerability. An indication of this issue occurring can be seen in the system log messages, as shown below: user@host> show log messages | match "Failed to complete DFE tuning" fpc4 smic_phy_dfe_tuning_state: et-4/1/6 - Failed to complete DFE tuning (count 3) and interface will be in a permanently down state: user@host> show interfaces et-4/1/6 terse Interface Admin Link Proto Local Remote et-4/1/6 up down et-4/1/6.0 up down aenet --> ae101.0 This issue affects Juniper Networks Junos OS: 16.1 versions prior to 16.1R7-S7 on MX Series; 17.1R1 and later versions prior to 17.2R3-S3 on MX Series; 17.3 versions prior to 17.3R3-S8 on MX Series; 17.4 versions prior to 17.4R2-S11, 17.4R3-S1 on MX Series, SRX4600; 18.1 versions prior to 18.1R3-S10 on MX Series, EX9200 Series, SRX4600; 18.2 versions prior to 18.2R3-S3 on MX Series, EX9200 Series, SRX4600; 18.3 versions prior to 18.3R3-S1 on MX Series, EX9200 Series, SRX4600; 18.4 versions prior to 18.4R2-S3, 18.4R3 on MX Series, EX9200 Series, SRX4600; 19.1 versions prior to 19.1R2-S1, 19.1R3 on MX Series, EX9200 Series, SRX4600; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series, EX9200 Series, SRX4600; 19.3 versions prior to 19.3R2 on MX Series, EX9200 Series, SRX4600. This issue does not affect Juniper Networks Junos OS versions prior to 16.1R1.
- Record
CVE-2021-0290- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 3.3 Low
AV:A/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-755
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-0290 is a medium vulnerability (CVSS 6.5) in Juniper Junos, published July 15, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 32nd percentile. No source names a fixed version.