NULL pointer dereference in Apple Ipados
CVE-2021-23841
The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based on the issuer and serial number data contained within an X509 certificate. However it fails to correctly handle any errors that may occur while parsing the issuer field (which might occur if the issuer field is maliciously constructed). This may subsequently result in a NULL pointer deref and a crash leading to a potential denial of service attack. The function X509_issuer_and_serial_hash() is never directly called by OpenSSL itself so applications are only vulnerable if they use this function directly and they use it on certificates that may have been obtained from untrusted sources. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).
EPSS: 0.075 (93.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Apple Ipados
- Apple Iphone_os
- Apple Macos
- Apple Safari
- Netapp Oncommand_insight
- Netapp Oncommand_workflow_automation
- Netapp Snapcenter
- Openssl — versions Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i), Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x)
- Oracle Business_intelligence — versions 5.5.0.0.0, 5.9.0.0.0, 12.2.1.3.0
- Oracle Communications_cloud_native_core_policy — versions 1.15.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- openssl-security@openssl.org (Vendor Advisory)
- openssl-security@openssl.org
- openssl-security@openssl.org
- openssl-security@openssl.org (vendor-advisory, Third Party Advisory)
- openssl-security@openssl.org (vendor-advisory, Third Party Advisory)
- openssl-security@openssl.org (mailing-list, Mailing List, Third Party Advisory)
- openssl-security@openssl.org (mailing-list, Mailing List, Third Party Advisory)
- openssl-security@openssl.org (mailing-list, Mailing List, Third Party Advisory)
- openssl-security@openssl.org (Patch, Third Party Advisory)
- openssl-security@openssl.org (Third Party Advisory)
Frequently asked questions
- What is CVE-2021-23841?
- CVE-2021-23841 is a medium-severity vulnerability in Apple Ipados, classified under NULL Pointer Dereference. CVSS score: 5.9/10. Published 2021-02-16.
- How severe is CVE-2021-23841?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2021-23841 known to be exploited?
- 29 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.