CVE-2024-39556

A Stack-Based Buffer Overflow vulnerability in Juniper Networks Junos OS and Juniper Networks Junos OS Evolved may allow a local, low-privileged attacker with access to the CLI the ability to load a malicious certificate file, leading to a limited Denial of Service (DoS) or privileged code execution.

By exploiting the set security certificates command with a crafted certificate file, a malicious attacker with access to the CLI could cause a crash of the command management daemon (mgd), limited to the local users command interpreter, or potentially trigger a stack-based buffer overflow.

This issue affects:

 Junos OS:

• All versions before 21.4R3-S7,
• from 22.1 before 22.1R3-S6,
• from 22.2 before 22.2R3-S4,
• from 22.3 before 22.3R3-S3,
• from 22.4 before 22.4R3-S2,
• from 23.2 before 23.2R2,
• from 23.4 before 23.4R1-S1, 23.4R2; 

Junos OS Evolved:

• All versions before 21.4R3-S7-EVO,
• from 22.1-EVO before 22.1R3-S6-EVO,
• from 22.2-EVO before 22.2R3-S4-EVO,
• from 22.3-EVO before 22.3R3-S3-EVO,
• from 22.4-EVO before 22.4R3-S2-EVO,
• from 23.2-EVO before 23.2R2-EVO,
• from 23.4-EVO before 23.4R1-S1-EVO, 23.4R2-EVO.

Weakness

A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

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].

References

• https://supportportal.juniper.net/JSA83016
• https://supportportal.juniper.net/JSA83016