Overview
- Description
- A sym-linked file accessed via the repair function in Avast Antivirus <24.2 on Windows may allow user to elevate privilege to delete arbitrary files or run processes as NT AUTHORITY\SYSTEM. The vulnerability exists within the "Repair" (settings -> troubleshooting -> repair) feature, which attempts to delete a file in the current user's AppData directory as NT AUTHORITY\SYSTEM. A low-privileged user can make a pseudo-symlink and a junction folder and point to a file on the system. This can provide a low-privileged user an Elevation of Privilege to win a race-condition which will re-create the system files and make Windows callback to a specially-crafted file which could be used to launch a privileged shell instance. This issue affects Avast Antivirus prior to 24.2.
- Source
- security@nortonlifelock.com
- NVD status
- Analyzed
Risk scores
CVSS 4.0
- Type
- Secondary
- Base score
- 7.3
- Impact score
- -
- Exploitability score
- -
- Vector string
- CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Severity
- HIGH
CVSS 3.1
- Type
- Primary
- Base score
- 7
- Impact score
- 5.9
- Exploitability score
- 1
- Vector string
- CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Severity
- HIGH
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:avast:antivirus:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E14E4791-47A8-4E8C-96E1-1E4A7F2D2F43",
"versionEndExcluding": "24.2"
}
],
"operator": "OR"
},
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"
}
],
"operator": "OR"
}
],
"operator": "AND"
}
]