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CVE-2021-22890

LOWCVSS 3.7/10EPSS 3.14%

Last modified

CVE-2021-22890 is a low-severity vulnerability rated 3.7/10 on the CVSS scale. curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. EPSS estimates a 3.14% chance of exploitation in the next 30 days.

Description

curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.

Metrics

CVSS 3.1
3.7/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability
3.14%

86.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
HaxxLibcurl>= 7.63.0, <= 7.75.0
FedoraprojectFedora32
FedoraprojectFedora33
FedoraprojectFedora34
NetappHci Management NodeAll versions
NetappSolidfireAll versions
NetappHci Storage NodeAll versions
BroadcomFabric Operating SystemAll versions
DebianDebian Linux9.0
SiemensSinec Infrastructure Network Services< 1.0.1.1
OracleCommunications Billing And Revenue Management12.0.0.3.0
OracleEssbase21.2
SplunkUniversal Forwarder>= 8.2.0, < 8.2.12
SplunkUniversal Forwarder>= 9.0.0, < 9.0.6
SplunkUniversal Forwarder9.1.0

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-22890?
curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly "short-cut" the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.
How severe is CVE-2021-22890?
CVE-2021-22890 has a CVSS score of 3.7/10 (LOW severity). The EPSS model estimates a 3.14% probability of exploitation in the next 30 days.
How do I fix CVE-2021-22890?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-22890?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST