SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-1559

If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data.

MEDIUM 5.9EPSS 17.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 17.1%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

Description

If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
17.14% probability · 97th percentile
CISA KEV
Not listed
Weakness
CWE-203
Affected
openssl/openssl · canonical/ubuntu linux · debian/debian linux · netapp/active iq unified manager · netapp/altavault · netapp/cloud backup · netapp/clustered data ontap antivirus connector · netapp/element software · netapp/hci management node · netapp/hyper converged infrastructure · netapp/oncommand insight · netapp/oncommand unified manager · netapp/oncommand unified manager core package · netapp/oncommand workflow automation · netapp/ontap select deploy · netapp/ontap select deploy administration utility · netapp/santricity smi-s provider · netapp/service processor · netapp/smi-s provider · netapp/snapcenter · +40 more
Source
openssl-security@openssl.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.