When a device using Juniper Networks Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv4 packets who may remotely take over the code execution of the JDHDCP process. This issue affect IPv4 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Junos | Juniper | 15.1-r7 (including) | 15.1-r7 (including) |
| Junos | Juniper | 15.1-r7-s1 (including) | 15.1-r7-s1 (including) |
| Junos | Juniper | 15.1-r7-s2 (including) | 15.1-r7-s2 (including) |
| Junos | Juniper | 15.1-r7-s3 (including) | 15.1-r7-s3 (including) |
| Junos | Juniper | 15.1-r7-s4 (including) | 15.1-r7-s4 (including) |
| Junos | Juniper | 15.1-r7-s5 (including) | 15.1-r7-s5 (including) |
| Junos | Juniper | 15.1x49-d10 (including) | 15.1x49-d10 (including) |
| Junos | Juniper | 15.1x49-d110 (including) | 15.1x49-d110 (including) |
| Junos | Juniper | 15.1x49-d140 (including) | 15.1x49-d140 (including) |
| Junos | Juniper | 15.1x49-d150 (including) | 15.1x49-d150 (including) |
| Junos | Juniper | 15.1x49-d170 (including) | 15.1x49-d170 (including) |
| Junos | Juniper | 15.1x49-d180 (including) | 15.1x49-d180 (including) |
| Junos | Juniper | 15.1x49-d190 (including) | 15.1x49-d190 (including) |
| Junos | Juniper | 15.1x49-d20 (including) | 15.1x49-d20 (including) |
| Junos | Juniper | 15.1x49-d30 (including) | 15.1x49-d30 (including) |
| Junos | Juniper | 15.1x49-d35 (including) | 15.1x49-d35 (including) |
| Junos | Juniper | 15.1x49-d40 (including) | 15.1x49-d40 (including) |
| Junos | Juniper | 15.1x49-d50 (including) | 15.1x49-d50 (including) |
| Junos | Juniper | 15.1x49-d55 (including) | 15.1x49-d55 (including) |
| Junos | Juniper | 15.1x49-d60 (including) | 15.1x49-d60 (including) |
| Junos | Juniper | 15.1x49-d65 (including) | 15.1x49-d65 (including) |
| Junos | Juniper | 15.1x49-d70 (including) | 15.1x49-d70 (including) |
| Junos | Juniper | 15.1x49-d75 (including) | 15.1x49-d75 (including) |
| Junos | Juniper | 15.1x49-d80 (including) | 15.1x49-d80 (including) |
| Junos | Juniper | 15.1x49-d90 (including) | 15.1x49-d90 (including) |
| Junos | Juniper | 15.1x53-d20 (including) | 15.1x53-d20 (including) |
| Junos | Juniper | 15.1x53-d21 (including) | 15.1x53-d21 (including) |
| Junos | Juniper | 15.1x53-d210 (including) | 15.1x53-d210 (including) |
| Junos | Juniper | 15.1x53-d25 (including) | 15.1x53-d25 (including) |
| Junos | Juniper | 15.1x53-d30 (including) | 15.1x53-d30 (including) |
| Junos | Juniper | 15.1x53-d31 (including) | 15.1x53-d31 (including) |
| Junos | Juniper | 15.1x53-d32 (including) | 15.1x53-d32 (including) |
| Junos | Juniper | 15.1x53-d33 (including) | 15.1x53-d33 (including) |
| Junos | Juniper | 15.1x53-d34 (including) | 15.1x53-d34 (including) |
| Junos | Juniper | 15.1x53-d40 (including) | 15.1x53-d40 (including) |
| Junos | Juniper | 15.1x53-d45 (including) | 15.1x53-d45 (including) |
| Junos | Juniper | 15.1x53-d470 (including) | 15.1x53-d470 (including) |
| Junos | Juniper | 15.1x53-d495 (including) | 15.1x53-d495 (including) |
| Junos | Juniper | 15.1x53-d56 (including) | 15.1x53-d56 (including) |
| Junos | Juniper | 15.1x53-d591 (including) | 15.1x53-d591 (including) |
| Junos | Juniper | 15.1x53-d60 (including) | 15.1x53-d60 (including) |
| Junos | Juniper | 15.1x53-d61 (including) | 15.1x53-d61 (including) |
| Junos | Juniper | 15.1x53-d62 (including) | 15.1x53-d62 (including) |
| Junos | Juniper | 15.1x53-d63 (including) | 15.1x53-d63 (including) |
| Junos | Juniper | 15.1x53-d65 (including) | 15.1x53-d65 (including) |
| Junos | Juniper | 15.1x53-d70 (including) | 15.1x53-d70 (including) |
| Junos | Juniper | 16.1 (including) | 16.1 (including) |
| Junos | Juniper | 16.1-r1 (including) | 16.1-r1 (including) |
| Junos | Juniper | 16.1-r2 (including) | 16.1-r2 (including) |
| Junos | Juniper | 16.1-r3 (including) | 16.1-r3 (including) |
| Junos | Juniper | 16.1-r3-s10 (including) | 16.1-r3-s10 (including) |
| Junos | Juniper | 16.1-r4 (including) | 16.1-r4 (including) |
| Junos | Juniper | 16.1-r5-s4 (including) | 16.1-r5-s4 (including) |
| Junos | Juniper | 16.1-r6-s1 (including) | 16.1-r6-s1 (including) |
| Junos | Juniper | 16.1-r7 (including) | 16.1-r7 (including) |
| Junos | Juniper | 16.1-r7-s4 (including) | 16.1-r7-s4 (including) |
| Junos | Juniper | 16.1-r7-s5 (including) | 16.1-r7-s5 (including) |
| Junos | Juniper | 16.2 (including) | 16.2 (including) |
| Junos | Juniper | 16.2-r1 (including) | 16.2-r1 (including) |
| Junos | Juniper | 16.2-r2 (including) | 16.2-r2 (including) |
| Junos | Juniper | 16.2-r2-s1 (including) | 16.2-r2-s1 (including) |
| Junos | Juniper | 16.2-r2-s2 (including) | 16.2-r2-s2 (including) |
| Junos | Juniper | 16.2-r2-s5 (including) | 16.2-r2-s5 (including) |
| Junos | Juniper | 16.2-r2-s6 (including) | 16.2-r2-s6 (including) |
| Junos | Juniper | 16.2-r2-s7 (including) | 16.2-r2-s7 (including) |
| Junos | Juniper | 16.2-r2-s8 (including) | 16.2-r2-s8 (including) |
| Junos | Juniper | 16.2-r2-s9 (including) | 16.2-r2-s9 (including) |
| Junos | Juniper | 17.1 (including) | 17.1 (including) |
| Junos | Juniper | 17.1-r1 (including) | 17.1-r1 (including) |
| Junos | Juniper | 17.1-r2-s1 (including) | 17.1-r2-s1 (including) |
| Junos | Juniper | 17.1-r2-s10 (including) | 17.1-r2-s10 (including) |
| Junos | Juniper | 17.1-r2-s2 (including) | 17.1-r2-s2 (including) |
| Junos | Juniper | 17.1-r2-s3 (including) | 17.1-r2-s3 (including) |
| Junos | Juniper | 17.1-r2-s4 (including) | 17.1-r2-s4 (including) |
| Junos | Juniper | 17.1-r2-s5 (including) | 17.1-r2-s5 (including) |
| Junos | Juniper | 17.1-r2-s6 (including) | 17.1-r2-s6 (including) |
| Junos | Juniper | 17.1-r2-s7 (including) | 17.1-r2-s7 (including) |
| Junos | Juniper | 17.1-r3 (including) | 17.1-r3 (including) |
| Junos | Juniper | 17.2 (including) | 17.2 (including) |
| Junos | Juniper | 17.2-r1-s2 (including) | 17.2-r1-s2 (including) |
| Junos | Juniper | 17.2-r1-s4 (including) | 17.2-r1-s4 (including) |
| Junos | Juniper | 17.2-r1-s7 (including) | 17.2-r1-s7 (including) |
| Junos | Juniper | 17.2-r1-s8 (including) | 17.2-r1-s8 (including) |
| Junos | Juniper | 17.2-r2-s6 (including) | 17.2-r2-s6 (including) |
| Junos | Juniper | 17.2-r2-s7 (including) | 17.2-r2-s7 (including) |
| Junos | Juniper | 17.2-r3-s1 (including) | 17.2-r3-s1 (including) |
| Junos | Juniper | 17.2-r3-s2 (including) | 17.2-r3-s2 (including) |
| Junos | Juniper | 17.3 (including) | 17.3 (including) |
| Junos | Juniper | 17.3-r1-s1 (including) | 17.3-r1-s1 (including) |
| Junos | Juniper | 17.3-r2 (including) | 17.3-r2 (including) |
| Junos | Juniper | 17.3-r2-s1 (including) | 17.3-r2-s1 (including) |
| Junos | Juniper | 17.3-r2-s2 (including) | 17.3-r2-s2 (including) |
| Junos | Juniper | 17.3-r3-s1 (including) | 17.3-r3-s1 (including) |
| Junos | Juniper | 17.3-r3-s2 (including) | 17.3-r3-s2 (including) |
| Junos | Juniper | 17.3-r3-s3 (including) | 17.3-r3-s3 (including) |
| Junos | Juniper | 17.3-r3-s4 (including) | 17.3-r3-s4 (including) |
| Junos | Juniper | 17.3-r3-s5 (including) | 17.3-r3-s5 (including) |
| Junos | Juniper | 17.4 (including) | 17.4 (including) |
| Junos | Juniper | 17.4-r1 (including) | 17.4-r1 (including) |
| Junos | Juniper | 17.4-r1-s1 (including) | 17.4-r1-s1 (including) |
| Junos | Juniper | 17.4-r1-s2 (including) | 17.4-r1-s2 (including) |
| Junos | Juniper | 17.4-r1-s4 (including) | 17.4-r1-s4 (including) |
| Junos | Juniper | 17.4-r1-s6 (including) | 17.4-r1-s6 (including) |
| Junos | Juniper | 17.4-r1-s7 (including) | 17.4-r1-s7 (including) |
| Junos | Juniper | 17.4-r2 (including) | 17.4-r2 (including) |
| Junos | Juniper | 17.4-r2-s1 (including) | 17.4-r2-s1 (including) |
| Junos | Juniper | 17.4-r2-s3 (including) | 17.4-r2-s3 (including) |
| Junos | Juniper | 17.4-r2-s4 (including) | 17.4-r2-s4 (including) |
| Junos | Juniper | 17.4-r2-s5 (including) | 17.4-r2-s5 (including) |
| Junos | Juniper | 17.4-r2-s6 (including) | 17.4-r2-s6 (including) |
| Junos | Juniper | 18.1-r3-s5 (including) | 18.1-r3-s5 (including) |
| Junos | Juniper | 18.1-r3-s6 (including) | 18.1-r3-s6 (including) |
| Junos | Juniper | 18.1-r3-s7 (including) | 18.1-r3-s7 (including) |
| Junos | Juniper | 18.2 (including) | 18.2 (including) |
| Junos | Juniper | 18.2-r1-s5 (including) | 18.2-r1-s5 (including) |
| Junos | Juniper | 18.2-r2-s1 (including) | 18.2-r2-s1 (including) |
| Junos | Juniper | 18.2-r2-s2 (including) | 18.2-r2-s2 (including) |
| Junos | Juniper | 18.2-r2-s3 (including) | 18.2-r2-s3 (including) |
| Junos | Juniper | 18.2-r2-s4 (including) | 18.2-r2-s4 (including) |
| Junos | Juniper | 18.2-r3 (including) | 18.2-r3 (including) |
| Junos | Juniper | 18.2-r3-s1 (including) | 18.2-r3-s1 (including) |
| Junos | Juniper | 18.2x75 (including) | 18.2x75 (including) |
| Junos | Juniper | 18.2x75-d20 (including) | 18.2x75-d20 (including) |
| Junos | Juniper | 18.2x75-d40 (including) | 18.2x75-d40 (including) |
| Junos | Juniper | 18.3 (including) | 18.3 (including) |
| Junos | Juniper | 18.3-r1 (including) | 18.3-r1 (including) |
| Junos | Juniper | 18.3-r1-s1 (including) | 18.3-r1-s1 (including) |
| Junos | Juniper | 18.3-r1-s2 (including) | 18.3-r1-s2 (including) |
| Junos | Juniper | 18.3-r1-s3 (including) | 18.3-r1-s3 (including) |
| Junos | Juniper | 18.3-r1-s4 (including) | 18.3-r1-s4 (including) |
| Junos | Juniper | 18.3-r1-s5 (including) | 18.3-r1-s5 (including) |
| Junos | Juniper | 18.3-r2 (including) | 18.3-r2 (including) |
| Junos | Juniper | 18.4 (including) | 18.4 (including) |
| Junos | Juniper | 18.4-r1 (including) | 18.4-r1 (including) |
| Junos | Juniper | 18.4-r1-s1 (including) | 18.4-r1-s1 (including) |
| Junos | Juniper | 18.4-r1-s2 (including) | 18.4-r1-s2 (including) |
| Junos | Juniper | 18.4-r1-s3 (including) | 18.4-r1-s3 (including) |
| Junos | Juniper | 18.4-r1-s4 (including) | 18.4-r1-s4 (including) |
| Junos | Juniper | 18.4-r2 (including) | 18.4-r2 (including) |
| Junos | Juniper | 19.1-r1 (including) | 19.1-r1 (including) |
| Junos | Juniper | 19.1-r1-s1 (including) | 19.1-r1-s1 (including) |
| Junos | Juniper | 19.1-r1-s2 (including) | 19.1-r1-s2 (including) |
| Junos | Juniper | 19.2-r1 (including) | 19.2-r1 (including) |
| Junos | Juniper | 19.2-r1-s1 (including) | 19.2-r1-s1 (including) |
| Junos | Juniper | 19.2-r1-s2 (including) | 19.2-r1-s2 (including) |
The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:
In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.