How severe is CVE-2017-2624?

CVE-2017-2624 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2017-2624 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-2624?

CVE-2017-2624 primarily affects X.org X Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-2624?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-2624 published?

CVE-2017-2624 was published on 2018-07-27 and last updated on 2026-06-17.

CVE-2017-2624

CVE-2017-2624 is a medium-severity vulnerability in X.org X Server with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 1.9
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: X.org X Server
Published: 2018-07-27
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2017-2624?: 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.
How severe is CVE-2017-2624?: CVE-2017-2624 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2017-2624 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-2624?: CVE-2017-2624 primarily affects X.org X Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-2624?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-2624 published?: CVE-2017-2624 was published on 2018-07-27 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*

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