CVE-2021-0249: Junos OS: SRX Series: A remote attacker may be able to cause a PFE buffer overflow to arbitrarily remotely execute code or commands on the target device with UTM enabled.

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-22 · updated 2026-06-17
Weakness: CWE-120

Description

On SRX Series devices configured with UTM services a buffer overflow vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS may allow an attacker to arbitrarily execute code or commands on the target to take over or otherwise impact the device by sending crafted packets to or through the device. This issue affects: Juniper Networks Junos OS on SRX Series: 15.1X49 versions prior to 15.1X49-D190; 17.4 versions prior to 17.4R2-S9; 17.4R3 and later versions prior to 18.1R3-S9; 18.2 versions prior to 18.2R3-S1; 18.3 versions prior to 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S4, 19.1R2; 19.2 versions prior to 19.2R1-S1, 19.2R2. An indicator of compromise can be the following text in the UTM log: RT_UTM: AV_FILE_NOT_SCANNED_PASSED_MT:

Affected products

Juniper Junos OS: 15.1x49, 15.1x49-d10, 15.1x49-d100, 15.1x49-d110, 15.1x49-d120, 15.1x49-d130 (+107)

References

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