CVE-2024-21606Junos OS: SRX Series: When "tcp-encap" is configured and specific packets are received flowd will crash
- 7.5HighCVSS base score
- 0.56%Exploitation in 30 daysEPSS · top 53% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A Double Free vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX Series allows a network-based, unauthenticated attacker to cause a Denial of Service (DoS). In a remote access VPN scenario, if a "tcp-encap-profile" is configured and a sequence of specific packets is received, a flowd crash and restart will be observed. This issue affects Juniper Networks Junos OS on SRX Series: * All versions earlier than 20.4R3-S8; * 21.2 versions earlier than 21.2R3-S6; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3-S3; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S1; * 22.4 versions earlier than 22.4R2-S2, 22.4R3.
Timeline
ID reserved
By juniper
- 16 days later
· 16 days later
Published
- 17 months later
· 17 months 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 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.56% · top 53% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected < 20.4R3-S8
- affected 21.2 – < 21.2R3-S6
- affected 21.3 – < 21.3R3-S5
- affected 21.4 – < 21.4R3-S5
- affected 22.1 – < 22.1R3-S3
- affected 22.2 – < 22.2R3-S3
- affected 22.3 – < 22.3R3-S1
- affected 22.4 – < 22.4R2-S2, 22.4R3
What to do
Solution: The following software releases have been updated to resolve this specific issue: Junos OS 20.4R3-S8, 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S3, 22.2R3-S3, 22.3R3-S1, 22.4R2-S2, 22.4R3, 23.2R1, and all subsequent releases.
Workaround: There are no known workarounds for this issue.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References
References2
- https://supportportal.juniper.net/JSA75747 (opens in a new tab)vendor-advisoryx_transferred
- https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H (opens in a new tab)technical-descriptionx_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-2024-19254 (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-2024-21606)Record last updated .