Null pointer dereference vulnerability in the function be_uint32_read() - advancecomp-2.1
Loginsoft-2018-1049
February 13, 2019
CVE Number
CVE-2019-8379
CWE
CWE-476: NULL Pointer Dereference
Product Details
AdvanceCOMP contains recompression utilities for your .zip archives,.png images, .mng video clips and .gz files.
URL: Source forge
Vulnerable Versions
2.1
Vulnerability Details
During our research on advancecomp, we found null pointer dereference in this function be_uint32_read() located in endianrw.h. The same can be triggered by sending a crafted abc file to the binary. It allows an attacker to cause Denial of Service (Segmentation fault) or possibly have unspecified other impact when a victim opens a specially crafted file.
SYNOPSIS
As per our research the vulnerability exists in function be_uint32_read( ) at file endianrw.h . The function mng_print( ) takes the arguments as string and path which invokes the function png_print_chunk () takes a part of png data, while checking the switch case statement ,if the type value in switch case is at address 0x4d484452, When a crafted file is passed to the binary advmng while reading the data in function be_uint_read( ) at return (unsigned)ptr8[3] | (unsigned)ptr8[2] << 8 | (unsigned)ptr8[1] << 16 | (unsigned)ptr8[0] << 24;The value of data in ptr is NULL which is of type pointer, while dereferencing to data the vulnerability Null pointer dereference is triggered.
Vulnerable code
switch (type) {
case ADV_MNG_CN_MHDR :
cout << " width:" << be_uint32_read(data+0) << " height:" << be_uint32_read(data+4) << " frequency:" << be_uint32_read(data+8);
return (unsigned)ptr8[3] | (unsigned)ptr8[2] << 8 | (unsigned)ptr8[1] << 16 | (unsigned)ptr8[0] << 24;
Analysis
198 return (unsigned)ptr8[3] | (unsigned)ptr8[2] less than 8 | (unsigned)ptr8[1] less than 16 | (unsigned)ptr8[0] less than 24;
[ Legend: Modified register | Code | Heap | Stack | String ]
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────[ registers ]────
$rax : 0x3
$rbx : 0x6567e0 → 0x00007ffff7bb4960 → 0x00007ffff7943c00 → std::basic_ostream mov rax, QWORD PTR [rip+0x272721] # 0x7ffff7bb6328
$rcx : 0x3a687464
$rdx : 0x7ffff7bb4960 → 0x00007ffff7943c00 → std::basic_ostream mov rax, QWORD PTR [rip+0x272721] # 0x7ffff7bb6328
$rsp : 0x7fffffffdb00 → 0x00007fffffffdb50 → 0x00007fffffffdc20 → 0x00007fffffffdc90 → 0x00007fffffffdd70 → 0x00007fffffffddc0 → 0x00000000004439e0 → push r15
$rbp : 0x7fffffffdb00 → 0x00007fffffffdb50 → 0x00007fffffffdc20 → 0x00007fffffffdc90 → 0x00007fffffffdd70 → 0x00007fffffffddc0 → 0x00000000004439e0 → push r15
$rsi : 0x0
$rdi : 0x0
$rip : 0x409372 → movzx eax, BYTE PTR [rax]
$r8 : 0x7
$r9 : 0x7ffff730b620 → 0x00000000fbad2a84
$r10 : 0x1
$r11 : 0x1002
$r12 : 0x4031c0 → xor ebp, ebp
$r13 : 0x7fffffffdea0 → 0x000000000000000c
$r14 : 0x0
$r15 : 0x0
$eflags: [carry PARITY adjust zero sign trap INTERRUPT direction overflow RESUME virtualx86 identification]
$gs: 0x0000 $cs: 0x0033 $ss: 0x002b $ds: 0x0000 $fs: 0x0000 $es: 0x0000
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────[ stack ]────
0x00007fffffffdb00│+0x00: 0x00007fffffffdb50 → 0x00007fffffffdc20 → 0x00007fffffffdc90 → 0x00007fffffffdd70 → 0x00007fffffffddc0 → 0x00000000004439e0 → push r15 ← $rsp, $rbp
0x00007fffffffdb08│+0x08: 0x0000000000409e79 → mov esi, eax
0x00007fffffffdb10│+0x10: 0x0000000000000000
0x00007fffffffdb18│+0x18: 0x4d48445200000000
0x00007fffffffdb20│+0x20: 0x00007fffffffdb80 → 0x0000000000000000
0x00007fffffffdb28│+0x28: 0x000000000066ac50 → 0x0000000000000001
0x00007fffffffdb30│+0x30: 0x005244484dffdb50
0x00007fffffffdb38│+0x38: 0x27f2a27d5f1e4400
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────[ code:i386:x86-64 ]────
0x409364 rex.RB call 0xfffffffff8861cb2
0x40936a mov rax, QWORD PTR [rbp-0x8]
0x40936e add rax, 0x3
→ 0x409372 movzx eax, BYTE PTR [rax]
0x409375 movzx eax, al
0x409378 mov rdx, QWORD PTR [rbp-0x8]
0x40937c add rdx, 0x2
0x409380 movzx edx, BYTE PTR [rdx]
0x409383 movzx edx, dl
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────[ source:lib/endianrw.h+198 ]────
193 {
194 #ifdef USE_MSB
195 return cpu_uint32_read(ptr);
196 #else
197 const unsigned char* ptr8 = (const unsigned char*)ptr;
// ptr8=0x00007fffffffdaf8 → 0x0000000000000000
→ 198 return (unsigned)ptr8[3] | (unsigned)ptr8[2] less than 8 | (unsigned)ptr8[1] less than 16 | (unsigned)ptr8[0] less than 24;
199 #endif
200 }
201 /*@}*/
202
203 /** \name Write
─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────[ threads ]────
[#0] Id 1, Name: advmng, stopped, reason: SIGSEGV
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────[ trace ]────
[#0] 0x409372 → Name: be_uint32_read(ptr=0x0)
[#1] 0x409e79 → Name: png_print_chunk(type=0x4d484452, data=0x0, size=0x0)
[#2] 0x405c3b → Name: mng_print(path="/home/loginsoft/$POC")
[#3] 0x4077d4 → Name: list_all(argc=0x1, argv=0x7fffffffdf00)
[#4] 0x40861e → Name: process(argc=0xc, argv=0x7fffffffdea8)
[#5] 0x40895e → Name: main(argc=0xc, argv=0x7fffffffdea8)
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Tested environment
64-bit ubuntu 16.04 LTS
Proof of Concept
- advmng -l -0 -1 -2 -3 -4 -i 8 -r -e $POC
Timeline
Vendor Disclosure: 03-01-2019
Public Disclosure: 13-02-2019
Credit
Discovered by ACE Team - Loginsoft
