CVE-2021-22897 Information disclosure in https://github.com/curl/curl
Concurrent transfers in curl using Schannel may share cipher settings, potentially weakening transport security and exposing data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-22897?
CVE-2021-22897 is a medium-severity vulnerability in Haxx Curl, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
curl 7.61.0 through 7.76.1 suffers from exposure of data element to wrong session due to a mistake in the code for CURLOPT_SSL_CIPHER_LIST when libcurl is built to use the Schannel TLS library. The selected cipher set was stored in a single "static" variable in the library, which has the surprising side-effect that if an application sets up multiple concurrent transfers, the last one that sets the ciphers will accidentally control the set used by all transfers. In a worst-case scenario, this weakens transport security significantly.
Which versions are affected by CVE-2021-22897?
It affects 22 products.
Products include Haxx Curl, Netapp Cloud Backup, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410s Firmware, Netapp H500e Firmware and 16 more.
How do I fix CVE-2021-22897?
Upgrade to a fixed version.
Is CVE-2021-22897 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-22897 exists.
Other vulnerabilities in Haxx Curl
Sources
Also known as AZL-6358, CURL-CVE-2021-22897, ECHO-59c1-8ea7-4c79, GHSA-frcg-47mh-pj2g, JLSEC-2026-1333.