CVE-2021-1871
A logic issue was addressed with improved restrictions.
Critical
Known exploited
- Severity
- 9.8 / 10
- Critical · CVSS 3.1
- Exploit chance (EPSS)
- 7.00%
- Chance of exploitation in the next 30 days. Higher than 94.16% of scored vulnerabilities.
- Known exploited
- Yes
- In CISA's catalog since Nov 3, 2021
- Weakness
- NVD-CWE-noinfo
- Fix
- None yet
- No fixed version published
Exploited in the wild. Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability (Apple iOS, iPadOS, and macOS). Required action: Apply updates per vendor instructions. Due for U.S. federal agencies by Nov 17, 2021.
Description
A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 3.1 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
References
Advisories
Other links
Timeline
- Published
- Added to CISA's Known Exploited Vulnerabilities catalog
- Remediation due for U.S. federal agencies
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-5849-834g-hvw5 pypdf has possible infinite loop when hitting EOF in standard xref table during trailer search | High | Same weakness, |
| GHSA-cggf-277g-3q54 pypdf has possible large memory usage when parsing page tree | High | Same weakness, |
| GHSA-mfr5-77xh-9j7h pypdf has possible infinite loop when cloning dictionaries | High | Same weakness, |
| GHSA-3g3m-2fjr-6pw4 Glob: AbortSignal cancellation bypass allows post-timeout filesystem traversal | Medium | Same weakness, |
| GHSA-42gh-23hr-vphw pypdf has possible long runtimes when retrieving page labels | High | Same weakness, |
| GHSA-4vqv-7265-gm2w pypdf has possible large memory usage for exceptions in strict mode | High | Same weakness, |
| GHSA-62m5-6wh8-28x7 pypdf has possible long runtimes/large memory usage for encrypted PDF files | High | Same weakness, |
| GHSA-2qm8-x737-gmw5 pyasn1 has quadratic CPU consumption in constructed BIT STRING decoding | High | Same weakness, |
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