CVE-2024-21594

A Heap-based Buffer Overflow vulnerability in the Network Services Daemon (NSD) of Juniper Networks Junos OS allows authenticated, low privileged, local attacker to cause a Denial of Service (DoS).

On an SRX 5000 Series device, when executing a specific command repeatedly, memory is corrupted, which leads to a Flow Processing Daemon (flowd) crash.

The NSD process has to be restarted to restore services.

If this issue occurs, it can be checked with the following command:

user@host> request security policies check The following log message can also be observed:

Error: policies are out of sync for PFE node.fpc.pic. This issue affects:

Juniper Networks Junos OS on SRX 5000 Series

• All versions earlier than 20.4R3-S6;
• 21.1 versions earlier than 21.1R3-S5;
• 21.2 versions earlier than 21.2R3-S4;
• 21.3 versions earlier than 21.3R3-S3;
• 21.4 versions earlier than 21.4R3-S3;
• 22.1 versions earlier than 22.1R3-S1;
• 22.2 versions earlier than 22.2R3;
• 22.3 versions earlier than 22.3R2.

Weakness

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Affected Software

Potential Mitigations

• Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
• D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
• Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
• Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
• For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/92.html

References

• https://supportportal.juniper.net/JSA75733
• https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
• https://supportportal.juniper.net/JSA75733
• https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N