description: It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack.
problem types: CWE-385
affected:
{
product: xorg-x11-server
vendor: Xorg
versions:
status: affected, version: 1.19.0
}
metrics:
cvssV3_0: [
attackComplexity: HIGH
attackVector: LOCAL
availabilityImpact: NONE
baseScore: 5.9
baseSeverity: MEDIUM
confidentialityImpact: HIGH
integrityImpact: NONE
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
version: 3.0
]