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Advisory ID:
BRLY-2023-021

[BRLY-LOGOFAIL-2023-021] Out-of-bounds Read in DXE driver

June 19, 2024
Severity:
Medium
CVSS Score
6
Public Disclosure Date:
August 1, 2023
CVE ID:

Summary

BINARLY efiXplorer team has discovered a OOB Read vulnerability in DXE driver. Improper validation on JPEG marker length leads to multiple OOB Read operations during JPEG file processing in AMI firmware

Vendors Affected

Affected Products

Multiple
,

Potential Impact

By modifying the physical memory from runtime, an attacker can trigger a division by 0 due to a UINT32 overflow. This vulnerability is exploitable on both client and server platforms where S3 sleep is activated.

Summary

 BINARLY efiXplorer team has discovered a OOB Read vulnerability in DXE driver. Improper validation on JPEG marker length leads to multiple OOB Read operations during JPEG file processing in AMI firmware

Vulnerability Information

     
  • BINARLY internal vulnerability identifier: BRLY-LOGOFAIL-2023-021  
  • CVSS v3.1: 3.2 Low AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:L/A:N

Affected modules with confirmed impact by Binarly team

Module name Module GUID Module SHA256
AMITSE b1da0adf-4f77-4070-a88e-bffe1c60529a 439e73d391b7f7540f6faa58afdc2722bda250468d4a4f7f5f84228c1f77ddbe

Potential impact

This vulnerability will not lead to exploitation, however, it may lead to unexpected behaviour during JPEG file processing.

Vulnerability description

The pseudocode of the vulnerable function is shown below:

__int64 __fastcall GetDimensions(_BYTE *Image)
{
  char v2; // di
  unsigned __int8 v3; // r10
  unsigned __int8 v4; // bl
  unsigned __int8 MarkerType; // cl
  __int64 v6; // rax
  __int64 v8; // rax
  char v9; // al
  _BYTE *v10; // rdx
  _QWORD *v11; // r8
  unsigned __int8 v12; // r9
  __int64 v13; // rdx
  __int64 v14; // r11
  unsigned __int16 Len; // [rsp+30h] [rbp+8h]

  v2 = 0;
  v3 = 0;
  v4 = 0;
  if ( *Image != 0xFF || Image[1] != 0xD8 )
    return 0i64;
  while ( 1 )
  {
    MarkerType = Image[1];
    if ( MarkerType != 0xD8 )
      break;
    Image += 2;
LABEL_27:
    if ( *Image != 0xFF )
      return 0i64;
  }
  if ( MarkerType == 0xD9 )
    goto LABEL_30;
  if ( !MarkerType )
    return 0i64;
  if ( (MarkerType & 0xF0) == 0xE0 )
  {
LABEL_26:
    v9 = Image[3];
    v10 = Image + 2;
    LOBYTE(Len) = v9;
    HIBYTE(Len) = *v10;
    // BRLY-LOGOFAIL-2023-021: Image pointer is updated with value coming from the image (Len), without validation
    Image = &v10[Len];
    goto LABEL_27;
  }
  if ( MarkerType == 0xC0 )
  {
    v2 |= 2u;
    qword_95FC0 = (Image + 2);
    goto LABEL_26;
  }
  if ( MarkerType == 0xC4 )
  {
    v6 = v3++;
    qword_96560[v6] = (Image + 4);
    goto LABEL_26;
  }
  if ( (MarkerType & 0xF0) == 0xC0 )
  {
    if ( MarkerType > 0xC0u && MarkerType < 0xD0u )
      return 0i64;
    goto LABEL_26;
  }
  if ( MarkerType != 0xDA )
  {
    if ( MarkerType == 0xDB )
    {
      v8 = v4++;
      qword_95EA0[v8] = (Image + 4);
    }
    else if ( MarkerType == 0xDD )
    {
      LOBYTE(word_95490) = Image[5];
      HIBYTE(word_95490) = Image[4];
    }
    else if ( (MarkerType & 0xF8) != 0xD0
           && (MarkerType == 0xDC || MarkerType == 0xDE || MarkerType == 0xDF || (MarkerType + 16) > 0xEu) )
    {
      return 0i64;
    }
    goto LABEL_26;
  }
  qword_95F10 = (Image + 14);
LABEL_30:
  if ( v4 == 1 )
  {
    v4 = 2;
    qword_95EA8 = qword_95EA0[0] + 65;
  }
  if ( v3 == 1 )
  {
    v11 = &unk_96568;
    do
    {
      v12 = 0;
      v13 = 0i64;
      v14 = qword_96560[v3 - 1];
      do
        v12 += *(v14 + v13++ + 1);
      while ( v13 < 16 );
      ++v3;
      *v11++ = v12 + v14 + 17;
    }
    while ( v3 < 4u );
  }
  if ( v3 != 4 || v4 != 2 || (v2 & 2) == 0 )
    return 0i64;
  sub_5D26C(2u, 4u);
  return 1i64;
}

As we can see from the pseudocode, the JPEG Marker length, read from the image and stored in variable Len, is used to update the value of ImagePtr without any validation. The attacker can arbitrarly set wLen thus making ImagePtr point anywhere in memory.

Disclosure timeline

This bug is subject to a 90 day disclosure deadline. After 90 days elapsed or a patch has been made broadly available (whichever is earlier), the bug report will become visible to the public.

Disclosure Activity Date (YYYY-mm-dd)
Lenovo PSIRT is notified 2023-06-21
Lenovo ID (LEN-132940) is assigned 2023-06-22
CERT/CC is notified 2023-07-10
AMI PSIRT confirmed reported issues 2023-10-05
AMI PSIRT assigned CVE ID 2023-12-01
BINARLY public disclosure date 2024-06-19

Acknowledgements

BINARLY efiXplorer team

Tags
Vulnerability
supply chain
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