Vulnerability Details : CVE-2021-0270
On PTX Series and QFX10k Series devices with the "inline-jflow" feature enabled, a use after free weakness in the Packet Forwarding Engine (PFE) microkernel architecture of Juniper Networks Junos OS may allow an attacker to cause a Denial of Service (DoS) condition whereby one or more Flexible PIC Concentrators (FPCs) may restart. As this is a race condition situation this issue become more likely to be hit when network instability occurs, such as but not limited to BGP/IGP reconvergences, and/or further likely to occur when more active "traffic flows" are occurring through the device. When this issue occurs, it will cause one or more FPCs to restart unexpectedly. During FPC restarts core files will be generated. While the core file is generated traffic will be disrupted. Sustained receipt of large traffic flows and reconvergence-like situations may sustain the Denial of Service (DoS) situation. This issue affects: Juniper Networks Junos OS: 18.1 version 18.1R2 and later versions prior to 18.1R3-S10 on PTX Series, QFX10K Series.
Vulnerability category: Memory CorruptionDenial of service
Products affected by CVE-2021-0270
- cpe:2.3:o:juniper:junos:18.1:r2:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s1:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r2-s1:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r2-s2:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s2:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s3:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s4:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r2-s4:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s5:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s7:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s6:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s8:*:*:*:*:*:*
- cpe:2.3:o:juniper:junos:18.1:r3-s9:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-0270
0.12%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 45 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-0270
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.3
|
MEDIUM | AV:N/AC:M/Au:N/C:N/I:N/A:P |
8.6
|
2.9
|
NIST | |
5.9
|
MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
2.2
|
3.6
|
NIST | |
7.5
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
3.9
|
3.6
|
Juniper Networks, Inc. |
CWE ids for CVE-2021-0270
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The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.Assigned by:
- nvd@nist.gov (Primary)
- sirt@juniper.net (Secondary)
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by:
- nvd@nist.gov (Primary)
- sirt@juniper.net (Secondary)
References for CVE-2021-0270
-
https://kb.juniper.net/JSA11161
2021-04 Security Bulletin: Junos OS: PTX Series, QFX10K Series: A PTX/QFX FPC may restart unexpectedly with the "inline-Jflow" feature enabled on a large-scale deployment (CVE-2021-0270) - Juniper NetVendor Advisory
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https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/inline-flow-monitoring-ptx.html
Monitoring Network Traffic Flow on PTX Series Routers Using Inline Flow Monitoring - Technical Documentation - Support - Juniper NetworksVendor Advisory
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