An Improperly Controlled Sequential Memory Allocation vulnerability in the Juniper Networks Deep Packet Inspection-Decoder (JDPI-Decoder) Application Signature component of Junos OS's AppID service on SRX Series devices will stop the JDPI-Decoder from identifying dynamic application traffic, allowing an unauthenticated network-based attacker to send traffic to the target device using the JDPI-Decoder, designed to inspect dynamic application traffic and take action upon this traffic, to instead begin to not take action and to pass the traffic through. An example session can be seen by running the following command and evaluating the output. user@device# run show security flow session source-prefix <address/mask> extensive Session ID: <session ID>, Status: Normal, State: Active Policy name: <name of policy> Dynamic application: junos:UNKNOWN, <<<<< LOOK HERE Please note, the JDPI-Decoder and the AppID SigPack are both affected and both must be upgraded along with the operating system to address the matter. By default, none of this is auto-enabled for automatic updates. This issue affects: Juniper Networks any version of the JDPI-Decoder Engine prior to version 5.7.0-47 with the JDPI-Decoder enabled using any version of the AppID SigPack prior to version 1.550.2-31 (SigPack 3533) on Junos OS on SRX Series: All versions prior to 19.1R3-S10; 19.2 versions prior to 19.2R3-S7; 19.3 versions prior to 19.3R3-S8; 19.4 versions prior to 19.4R3-S11; 20.1 version 20.1R1 and later versions prior to 20.2R3-S7; 20.3 version 20.3R1 and later versions prior to 20.4R3-S6; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S4; 21.3 versions prior to 21.3R3-S3; 21.4 versions prior to 21.4R3-S3; 22.1 versions prior to 22.1R3-S1; 22.2 versions prior to 22.2R2-S1, 22.2R3; 22.3 versions prior to 22.3R1-S2, 22.3R2;
| Software | From | Fixed in |
|---|---|---|
| juniper / appid_service_sigpack | - | 1.550.2-31 |
| juniper / jdpi-decoder_engine | - | 5.7.0-47 |
| juniper / junos | 19.1-r1-s1 | 19.1-r1-s1.x |
| juniper / junos | 19.1-r1-s3 | 19.1-r1-s3.x |
| juniper / junos | 19.1-r1-s2 | 19.1-r1-s2.x |
| juniper / junos | 19.1-r1 | 19.1-r1.x |
| juniper / junos | 19.1 | 19.1.x |
| juniper / junos | 19.1-r2 | 19.1-r2.x |
| juniper / junos | 19.1-r1-s4 | 19.1-r1-s4.x |
| juniper / junos | 19.1-r2-s1 | 19.1-r2-s1.x |
| juniper / junos | 19.1-r3 | 19.1-r3.x |
| juniper / junos | 19.1-r3-s1 | 19.1-r3-s1.x |
| juniper / junos | 19.1-r3-s2 | 19.1-r3-s2.x |
| juniper / junos | 19.1-r3-s3 | 19.1-r3-s3.x |
| juniper / junos | 19.1-r1-s5 | 19.1-r1-s5.x |
| juniper / junos | 19.1-r3-s4 | 19.1-r3-s4.x |
| juniper / junos | 19.1-r2-s2 | 19.1-r2-s2.x |
| juniper / junos | 19.1-r1-s6 | 19.1-r1-s6.x |
| juniper / junos | 19.1-r3-s5 | 19.1-r3-s5.x |
| juniper / junos | 19.1-r3-s6 | 19.1-r3-s6.x |
| juniper / junos | 19.1-r3-s7 | 19.1-r3-s7.x |
| juniper / junos | 19.1-r2-s3 | 19.1-r2-s3.x |
| juniper / junos | 19.1-r3-s8 | 19.1-r3-s8.x |
| juniper / junos | 19.1-r3-s9 | 19.1-r3-s9.x |
| juniper / junos | 19.2-r3-s6 | 19.2-r3-s6.x |
| juniper / junos | 19.2-r1-s9 | 19.2-r1-s9.x |
| juniper / junos | 19.2-r3-s5 | 19.2-r3-s5.x |
| juniper / junos | 19.2-r1-s8 | 19.2-r1-s8.x |
| juniper / junos | 19.2-r1-s7 | 19.2-r1-s7.x |
| juniper / junos | 19.2-r3-s4 | 19.2-r3-s4.x |
| juniper / junos | 19.2-r3-s2 | 19.2-r3-s2.x |
| juniper / junos | 19.2-r3-s3 | 19.2-r3-s3.x |
| juniper / junos | 19.2-r1-s6 | 19.2-r1-s6.x |
| juniper / junos | 19.2-r3-s1 | 19.2-r3-s1.x |
| juniper / junos | 19.2-r2-s1 | 19.2-r2-s1.x |
| juniper / junos | 19.2-r1-s5 | 19.2-r1-s5.x |
| juniper / junos | 19.2-r2 | 19.2-r2.x |
| juniper / junos | 19.2-r3 | 19.2-r3.x |
| juniper / junos | 19.2-r1-s4 | 19.2-r1-s4.x |
| juniper / junos | 19.2-r1 | 19.2-r1.x |
| juniper / junos | 19.2 | 19.2.x |
| juniper / junos | 19.2-r1-s3 | 19.2-r1-s3.x |
| juniper / junos | 19.2-r1-s1 | 19.2-r1-s1.x |
| juniper / junos | 19.2-r1-s2 | 19.2-r1-s2.x |
| juniper / junos | 19.3 | 19.3.x |
| juniper / junos | 19.3-r1 | 19.3-r1.x |
| juniper / junos | 19.3-r2-s1 | 19.3-r2-s1.x |
| juniper / junos | 19.3-r1-s1 | 19.3-r1-s1.x |
| juniper / junos | 19.3-r2-s5 | 19.3-r2-s5.x |
| juniper / junos | 19.3-r3 | 19.3-r3.x |
| juniper / junos | 19.3-r2-s4 | 19.3-r2-s4.x |
| juniper / junos | 19.3-r2 | 19.3-r2.x |
| juniper / junos | 19.3-r2-s2 | 19.3-r2-s2.x |
| juniper / junos | 19.3-r2-s3 | 19.3-r2-s3.x |
| juniper / junos | 19.3-r3-s1 | 19.3-r3-s1.x |
| juniper / junos | 19.3-r3-s2 | 19.3-r3-s2.x |
| juniper / junos | 19.3-r3-s3 | 19.3-r3-s3.x |
| juniper / junos | 19.3-r3-s4 | 19.3-r3-s4.x |
| juniper / junos | 19.3-r2-s6 | 19.3-r2-s6.x |
| juniper / junos | 19.3-r3-s5 | 19.3-r3-s5.x |
| juniper / junos | 19.3-r3-s7 | 19.3-r3-s7.x |
| juniper / junos | 19.3-r2-s7 | 19.3-r2-s7.x |
| juniper / junos | 19.3-r3-s6 | 19.3-r3-s6.x |
| juniper / junos | 19.4-r2-s7 | 19.4-r2-s7.x |
| juniper / junos | 19.4-r3-s8 | 19.4-r3-s8.x |
| juniper / junos | 19.4-r3-s10 | 19.4-r3-s10.x |
| juniper / junos | 19.4-r3-s9 | 19.4-r3-s9.x |
| juniper / junos | 19.4-r2-s6 | 19.4-r2-s6.x |
| juniper / junos | 19.4-r3-s7 | 19.4-r3-s7.x |
| juniper / junos | 19.4 | 19.4.x |
| juniper / junos | 19.4-r3-s6 | 19.4-r3-s6.x |
| juniper / junos | 19.4-r2-s5 | 19.4-r2-s5.x |
| juniper / junos | 19.4-r2-s4 | 19.4-r2-s4.x |
| juniper / junos | 19.4-r3-s5 | 19.4-r3-s5.x |
| juniper / junos | 19.4-r1-s4 | 19.4-r1-s4.x |
| juniper / junos | 19.4-r3-s2 | 19.4-r3-s2.x |
| juniper / junos | 19.4-r3-s3 | 19.4-r3-s3.x |
| juniper / junos | 19.4-r3-s4 | 19.4-r3-s4.x |
| juniper / junos | 19.4-r2-s2 | 19.4-r2-s2.x |
| juniper / junos | 19.4-r3-s1 | 19.4-r3-s1.x |
| juniper / junos | 19.4-r2-s3 | 19.4-r2-s3.x |
| juniper / junos | 19.4-r1-s3 | 19.4-r1-s3.x |
| juniper / junos | 19.4-r2 | 19.4-r2.x |
| juniper / junos | 19.4-r2-s1 | 19.4-r2-s1.x |
| juniper / junos | 19.4-r1-s1 | 19.4-r1-s1.x |
| juniper / junos | 19.4-r3 | 19.4-r3.x |
| juniper / junos | 19.4-r1-s2 | 19.4-r1-s2.x |
| juniper / junos | 19.4-r1 | 19.4-r1.x |
| juniper / junos | 20.1-r1-s1 | 20.1-r1-s1.x |
| juniper / junos | 20.1-r1 | 20.1-r1.x |
| juniper / junos | 20.1-r1-s2 | 20.1-r1-s2.x |
| juniper / junos | 20.1-r1-s3 | 20.1-r1-s3.x |
| juniper / junos | 20.1-r1-s4 | 20.1-r1-s4.x |
| juniper / junos | 20.1-r3 | 20.1-r3.x |
| juniper / junos | 20.1-r2 | 20.1-r2.x |
| juniper / junos | 20.1-r2-s1 | 20.1-r2-s1.x |
| juniper / junos | 20.1-r2-s2 | 20.1-r2-s2.x |
| juniper / junos | 20.1-r3-s1 | 20.1-r3-s1.x |
| juniper / junos | 20.1-r3-s2 | 20.1-r3-s2.x |
| juniper / junos | 20.1-r3-s3 | 20.1-r3-s3.x |
| juniper / junos | 20.1 | 20.1.x |
| juniper / junos | 20.1-r3-s4 | 20.1-r3-s4.x |
| juniper / junos | 20.1-r3-s5 | 20.1-r3-s5.x |
| juniper / junos | 20.2-r3-s5 | 20.2-r3-s5.x |
| juniper / junos | 20.2-r3-s6 | 20.2-r3-s6.x |
| juniper / junos | 20.2-r3-s4 | 20.2-r3-s4.x |
| juniper / junos | 20.2 | 20.2.x |
| juniper / junos | 20.2-r3-s3 | 20.2-r3-s3.x |
| juniper / junos | 20.2-r3-s2 | 20.2-r3-s2.x |
| juniper / junos | 20.2-r2-s2 | 20.2-r2-s2.x |
| juniper / junos | 20.2-r2-s3 | 20.2-r2-s3.x |
| juniper / junos | 20.2-r3 | 20.2-r3.x |
| juniper / junos | 20.2-r3-s1 | 20.2-r3-s1.x |
| juniper / junos | 20.2-r1-s3 | 20.2-r1-s3.x |
| juniper / junos | 20.2-r2 | 20.2-r2.x |
| juniper / junos | 20.2-r2-s1 | 20.2-r2-s1.x |
| juniper / junos | 20.2-r1-s1 | 20.2-r1-s1.x |
| juniper / junos | 20.2-r1-s2 | 20.2-r1-s2.x |
| juniper / junos | 20.2-r1 | 20.2-r1.x |
| juniper / junos | 20.3-r1-s1 | 20.3-r1-s1.x |
| juniper / junos | 20.3-r1 | 20.3-r1.x |
| juniper / junos | 20.3-r2-s1 | 20.3-r2-s1.x |
| juniper / junos | 20.3-r2 | 20.3-r2.x |
| juniper / junos | 20.3-r3 | 20.3-r3.x |
| juniper / junos | 20.3-r3-s1 | 20.3-r3-s1.x |
| juniper / junos | 20.3-r1-s2 | 20.3-r1-s2.x |
| juniper / junos | 20.3-r3-s3 | 20.3-r3-s3.x |
| juniper / junos | 20.3 | 20.3.x |
| juniper / junos | 20.3-r3-s2 | 20.3-r3-s2.x |
| juniper / junos | 20.3-r3-s6 | 20.3-r3-s6.x |
| juniper / junos | 20.3-r3-s4 | 20.3-r3-s4.x |
| juniper / junos | 20.3-r3-s5 | 20.3-r3-s5.x |
| juniper / junos | 20.4-r3-s4 | 20.4-r3-s4.x |
| juniper / junos | 20.4-r3-s5 | 20.4-r3-s5.x |
| juniper / junos | 20.4-r3-s6 | 20.4-r3-s6.x |
| juniper / junos | 20.4 | 20.4.x |
| juniper / junos | 20.4-r3-s2 | 20.4-r3-s2.x |
| juniper / junos | 20.4-r3-s3 | 20.4-r3-s3.x |
| juniper / junos | 20.4-r3-s1 | 20.4-r3-s1.x |
| juniper / junos | 20.4-r2-s2 | 20.4-r2-s2.x |
| juniper / junos | 20.4-r3 | 20.4-r3.x |
| juniper / junos | 20.4-r2-s1 | 20.4-r2-s1.x |
| juniper / junos | 20.4-r1-s1 | 20.4-r1-s1.x |
| juniper / junos | 20.4-r2 | 20.4-r2.x |
| juniper / junos | 20.4-r1 | 20.4-r1.x |
| juniper / junos | 21.1-r1 | 21.1-r1.x |
| juniper / junos | 21.1-r1-s1 | 21.1-r1-s1.x |
| juniper / junos | 21.1-r2 | 21.1-r2.x |
| juniper / junos | 21.1-r3 | 21.1-r3.x |
| juniper / junos | 21.1-r2-s1 | 21.1-r2-s1.x |
| juniper / junos | 21.1-r3-s1 | 21.1-r3-s1.x |
| juniper / junos | 21.1 | 21.1.x |
| juniper / junos | 21.1-r2-s2 | 21.1-r2-s2.x |
| juniper / junos | 21.1-r3-s4 | 21.1-r3-s4.x |
| juniper / junos | 21.1-r3-s3 | 21.1-r3-s3.x |
| juniper / junos | 21.1-r3-s2 | 21.1-r3-s2.x |
| juniper / junos | 21.2-r3-s1 | 21.2-r3-s1.x |
| juniper / junos | 21.2-r3-s2 | 21.2-r3-s2.x |
| juniper / junos | 21.2-r3-s3 | 21.2-r3-s3.x |
| juniper / junos | 21.2-r1-s2 | 21.2-r1-s2.x |
| juniper / junos | 21.2-r2-s1 | 21.2-r2-s1.x |
| juniper / junos | 21.2-r2 | 21.2-r2.x |
| juniper / junos | 21.2-r2-s2 | 21.2-r2-s2.x |
| juniper / junos | 21.2-r3 | 21.2-r3.x |
| juniper / junos | 21.2 | 21.2.x |
| juniper / junos | 21.2-r1-s1 | 21.2-r1-s1.x |
| juniper / junos | 21.2-r1 | 21.2-r1.x |
| juniper / junos | 21.3-r1 | 21.3-r1.x |
| juniper / junos | 21.3-r2 | 21.3-r2.x |
| juniper / junos | 21.3 | 21.3.x |
| juniper / junos | 21.3-r3 | 21.3-r3.x |
| juniper / junos | 21.3-r3-s1 | 21.3-r3-s1.x |
| juniper / junos | 21.3-r1-s1 | 21.3-r1-s1.x |
| juniper / junos | 21.3-r1-s2 | 21.3-r1-s2.x |
| juniper / junos | 21.3-r2-s1 | 21.3-r2-s1.x |
| juniper / junos | 21.3-r2-s2 | 21.3-r2-s2.x |
| juniper / junos | 21.3-r3-s2 | 21.3-r3-s2.x |
| juniper / junos | 21.4-r3-s1 | 21.4-r3-s1.x |
| juniper / junos | 21.4-r3 | 21.4-r3.x |
| juniper / junos | 21.4-r2-s2 | 21.4-r2-s2.x |
| juniper / junos | 21.4-r3-s2 | 21.4-r3-s2.x |
| juniper / junos | 21.4-r1-s2 | 21.4-r1-s2.x |
| juniper / junos | 21.4-r1 | 21.4-r1.x |
| juniper / junos | 21.4-r1-s1 | 21.4-r1-s1.x |
| juniper / junos | 21.4-r2 | 21.4-r2.x |
| juniper / junos | 21.4-r2-s1 | 21.4-r2-s1.x |
| juniper / junos | 21.4 | 21.4.x |
| juniper / junos | 22.1-r1 | 22.1-r1.x |
| juniper / junos | 22.1-r1-s2 | 22.1-r1-s2.x |
| juniper / junos | 22.1-r2-s2 | 22.1-r2-s2.x |
| juniper / junos | 22.1-r1-s1 | 22.1-r1-s1.x |
| juniper / junos | 22.1-r2 | 22.1-r2.x |
| juniper / junos | 22.1-r2-s1 | 22.1-r2-s1.x |
| juniper / junos | 22.1-r3 | 22.1-r3.x |
| juniper / junos | 22.2-r1-s2 | 22.2-r1-s2.x |
| juniper / junos | 22.2-r1 | 22.2-r1.x |
| juniper / junos | 22.2-r1-s1 | 22.2-r1-s1.x |
| juniper / junos | 22.2-r2 | 22.2-r2.x |
| juniper / junos | 22.2-r3 | 22.2-r3.x |
| juniper / junos | 22.3-r1 | 22.3-r1.x |
| juniper / junos | 22.3-r1-s1 | 22.3-r1-s1.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.