CVE-2019-0040

CVE-2019-0040 is a critical-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Description

On Junos OS, rpcbind should only be listening to port 111 on the internal routing instance (IRI). External packets destined to port 111 should be dropped. Due to an information leak vulnerability, responses were being generated from the source address of the management interface (e.g. fxp0) thus disclosing internal addressing and existence of the management interface itself. A high rate of crafted packets destined to port 111 may also lead to a partial Denial of Service (DoS). Note: Systems with fxp0 disabled or unconfigured are not vulnerable to this issue. This issue only affects Junos OS releases based on FreeBSD 10 or higher (typically Junos OS 15.1+). Administrators can confirm whether systems are running a version of Junos OS based on FreeBSD 10 or higher by typing: user@junos> show version | match kernel JUNOS OS Kernel 64-bit [20181214.223829_fbsd-builder_stable_10] Affected releases are Juniper Networks Junos OS: 15.1 versions prior to 15.1F6-S12, 15.1R7-S4; 15.1X53 versions prior to 15.1X53-D236; 16.1 versions prior to 16.1R7-S1; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R1-S8; 17.3 versions prior to 17.3R2; 17.4 versions prior to 17.4R1-S1, 17.4R1-S7, 17.4R2. This issue does not affect Junos OS releases prior to 15.1.

Frequently asked questions

What is CVE-2019-0040?
On Junos OS, rpcbind should only be listening to port 111 on the internal routing instance (IRI). External packets destined to port 111 should be dropped. Due to an information leak vulnerability, responses were being generated from the source address of the management interface (e.g. fxp0) thus disclosing internal addressing and existence of the management interface itself. A high rate of crafted packets destined to port 111 may also lead to a partial Denial of Service (DoS). Note: Systems with fxp0 disabled or unconfigured are not vulnerable to this issue. This issue only affects Junos OS releases based on FreeBSD 10 or higher (typically Junos OS 15.1+). Administrators can confirm whether systems are running a version of Junos OS based on FreeBSD 10 or higher by typing: user@junos> show version | match kernel JUNOS OS Kernel 64-bit [20181214.223829_fbsd-builder_stable_10] Affected releases are Juniper Networks Junos OS: 15.1 versions prior to 15.1F6-S12, 15.1R7-S4; 15.1X53 versions prior to 15.1X53-D236; 16.1 versions prior to 16.1R7-S1; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R3; 17.2 versions prior to 17.2R1-S8; 17.3 versions prior to 17.3R2; 17.4 versions prior to 17.4R1-S1, 17.4R1-S7, 17.4R2. This issue does not affect Junos OS releases prior to 15.1.
How severe is CVE-2019-0040?
CVE-2019-0040 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2019-0040 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-0040?
CVE-2019-0040 primarily affects Juniper Junos. In total, 71 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-0040?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-0040 published?
CVE-2019-0040 was published on 2019-04-10 and last updated on 2026-06-17.

References

Affected products (71)

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