CVE-2021-0249Junos 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.
- 8.1HighCVSS base score
- 1.9%Exploitation in 30 daysEPSS · top 20% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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:
Timeline
ID reserved
By juniper
- 6 months later
· 6 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| juniperCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.9% · top 20% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected 15.1X49 – < 15.1X49-D190
- affected 17.4 – < 17.4R2-S9
- affected 18.1 – < 18.1R3-S9
- affected 18.2 – < 18.2R3-S1
- affected 18.3 – < 18.3R2-S3, 18.3R3
- affected 18.4 – < 18.4R2-S3, 18.4R3
- affected 19.1 – < 19.1R1-S4, 19.1R2
- affected 19.2 – < 19.2R1-S1, 19.2R2
What to do
Solution: The following software releases have been updated to resolve this specific issue: 15.1X49-D190, 17.4R2-S9, 18.1R3-S9, 18.2R3-S1, 18.3R2-S3, 18.3R3, 18.4R2-S3, 18.4R3, 19.1R1-S4, 19.1R2, 19.2R1-S1, 19.2R2, 19.3R1, and all subsequent releases.
Workaround: There are no available workarounds for this issue other than disabling UTM services.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References
References1
- https://kb.juniper.net/JSA11142 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2021-2868 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-0249)Record last updated .