CVE-2021-0284
Junos OS: Upon receipt of specific sequences of genuine packets destined to the device the kernel will crash and restart (vmcore)
A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an attacker to send specific sequences of packets to the device thereby causing a Denial of Service (DoS). By repeatedly sending these sequences of packets to the device, an attacker can sustain the Denial of Service (DoS) condition. The device will abnormally shut down as a result of these sent packets. A potential indicator of compromise will be the following message in the log files: "eventd[13955]: SYSTEM_ABNORMAL_SHUTDOWN: System abnormally shut down" This issue is only triggered by traffic destined to the device. Transit traffic will not trigger this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 17.3 versions prior to 17.3R3-S12; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.
Attack profile
How easy it is to exploit
- Attack vector
- 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
Junos OS: Upon receipt of specific sequences of genuine packets destined to the device the kernel will crash and restart (vmcore)
A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an attacker to send specific sequences of packets to the device thereby causing a Denial of Service (DoS). By repeatedly sending these sequences of packets to the device, an attacker can sustain the Denial of Service (DoS) condition. The device will abnormally shut down as a result of these sent packets. A potential indicator of compromise will be the following message in the log files: "eventd[13955]: SYSTEM_ABNORMAL_SHUTDOWN: System abnormally shut down" This issue is only triggered by traffic destined to the device. Transit traffic will not trigger this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 17.3 versions prior to 17.3R3-S12; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.
- Record
CVE-2021-0284- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2021-2903
A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an attacker to send specific sequences of packets to the device thereby causing a Denial of Service (DoS). By repeatedly sending these sequences of packets to the device, an attacker can sustain the Denial of Service (DoS) condition. The device will abnormally shut down as a result of these sent packets. A potential indicator of compromise will be the following message in the log files: "eventd[13955]: SYSTEM_ABNORMAL_SHUTDOWN: System abnormally shut down" This issue is only triggered by traffic destined to the device. Transit traffic will not trigger this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 17.3 versions prior to 17.3R3-S12; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.
- Record
EUVD-2021-2903- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4w4j-552x-2jff
A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an...
A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an attacker to send specific sequences of packets to the device thereby causing a Denial of Service (DoS). By repeatedly sending these sequences of packets to the device, an attacker can sustain the Denial of Service (DoS) condition. The device will abnormally shut down as a result of these sent packets. A potential indicator of compromise will be the following message in the log files: "eventd[13955]: SYSTEM_ABNORMAL_SHUTDOWN: System abnormally shut down" This issue is only triggered by traffic destined to the device. Transit traffic will not trigger this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 17.3 versions prior to 17.3R3-S12; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R2.
- Record
GHSA-4w4j-552x-2jff- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
NVD
A buffer overflow vulnerability in the TCP/IP stack of Juniper Networks Junos OS allows an attacker to send specific sequences of packets to the device thereby causing a Denial of Service (DoS). By repeatedly sending these sequences of packets to the device, an attacker can sustain the Denial of Service (DoS) condition. The device will abnormally shut down as a result of these sent packets. A potential indicator of compromise will be the following message in the log files: "eventd[13955]: SYSTEM_ABNORMAL_SHUTDOWN: System abnormally shut down" This issue is only triggered by traffic destined to the device. Transit traffic will not trigger this issue. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 17.3 versions prior to 17.3R3-S12; 18.4 versions prior to 18.4R2-S9, 18.4R3-S9; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S7, 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S2, 20.4R3; 21.1 versions prior to 21.1R2; 21.2 versions prior to 21.2R1-S1, 21.2R2.
- Record
CVE-2021-0284- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 7.8 High
AV:N/AC:L/Au:N/C:N/I:N/A:C - Weakness
- CWE-120
- 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-2021-0284 is a high vulnerability (CVSS 7.5) in Juniper Junos, published August 17, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.99%, the 62nd percentile. No source names a fixed version.