CVE-2021-3711: Debian Linux
Critical severity, CVSS 9.8. EPSS: 87.8% chance of exploitation in the next 30 days.
In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt(). Typically an application will call this function twice. The first time, on entry, the "out" parameter can be NULL and, on exit, the "outlen" parameter is populated with the buffer size required to hold the decrypted plaintext. The application can then allocate a sufficiently sized buffer and call EVP_PKEY_decrypt() again, but this time passing a non-NULL value for the "out" parameter. A bug in the implementation of the SM2 decryption code means that the calculation of the buffer size required to hold the plaintext returned by the first call to EVP_PKEY_decrypt() can be smaller than the actual size required by the second call. This can lead to a buffer overflow when EVP_PKEY_decrypt() is called by the application a second time with a buffer that is too small. A malicious attacker who is able present SM2 content for decryption to an application could cause attacker chosen data to overflow the buffer by up to a maximum of 62 bytes altering the contents of other data held after the buffer, possibly changing application behaviour or causing the application to crash. The location of the buffer is application dependent but is typically heap allocated. Fixed in OpenSSL 1.1.1l (Affected 1.1.1-1.1.1k).
Affected products
- Debian Debian Linux: version 10.0 only; version 11.0 only
- Netapp Active Iq Unified Manager: affected versions not specified
- Netapp Clustered Data Ontap: affected versions not specified
- Netapp Clustered Data Ontap Antivirus Connector: affected versions not specified
- Netapp E-Series Santricity OS Controller: from 11.0, up to and including 11.50.2
- Netapp Hci Management Node: affected versions not specified
- Netapp Manageability Software Development Kit: affected versions not specified
- Netapp Oncommand Insight: affected versions not specified
- Netapp Oncommand Workflow Automation: affected versions not specified
- Netapp Santricity Smi-S Provider: affected versions not specified
- Netapp Snapcenter: affected versions not specified
- Netapp Solidfire: affected versions not specified
- Netapp Storage Encryption: affected versions not specified
- OpenSSL OpenSSL: from 1.1.1, before 1.1.1l (fixed in 1.1.1l)
- Oracle Communications Cloud Native Core Security Edge Protection Proxy: version 1.7.0 only
- Oracle Communications Cloud Native Core Unified Data Repository: version 1.15.0 only
- Oracle Communications Session Border Controller: version 8.4 only; version 9.0 only
- Oracle Communications Unified Session Manager: version 8.2.5 only; version 8.4.5 only
- Oracle Enterprise Communications Broker: version 3.2.0 only; version 3.3.0 only
- Oracle Enterprise Session Border Controller: version 8.4 only; version 9.0 only
- Oracle Essbase: before 11.1.2.4.47 (fixed in 11.1.2.4.47); from 21.1, before 21.3 (fixed in 21.3)
- Oracle Health Sciences Inform Publisher: version 6.2.1.1 only; version 6.3.1.1 only
- Oracle Jd Edwards Enterpriseone Tools: before 9.2.6.3 (fixed in 9.2.6.3)
- Oracle Jd Edwards World Security: version a9.4 only
- Oracle MySQL Connectors: up to and including 8.0.27
- and 6 more
Published 2021-08-24. Last modified 2026-10-08.