xorg-x11-server: timing attack against MIT Cookie
Published Jul 27, 2018
7.0
HIGHCVSS 3.0
EPSS 0.67%
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.
Affected products
-
- Version 1.19.0StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Xorg | Xorg-X11-Server | n/a |
|
Configuration 2
- 7.0
No data.
Red Hat Enterprise Linux 5
xorg-x11-server
Will not fix
Red Hat Enterprise Linux 6
xorg-x11-server
Will not fix
Red Hat Enterprise Linux 7
xorg-x11-server
Will not fix
Red Hat Enterprise Linux 9
xorg-x11-server
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | xorg-x11-server | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | xorg-x11-server | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | xorg-x11-server | Will not fix | n/a |
| Red Hat Enterprise Linux 9 | xorg-x11-server | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
AV:L/AC:M/Au:N/C:P/I:N/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (14 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.67% (0.00669) | 50.20th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.68% (0.00675) | 47.19th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.04% (0.00037) | 8.09th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.15% (0.00154) | 53.09th | v3 (v2023.03.01) |
| Jul 21, 2023 | 0.15% (0.00154) | 50.95th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.13% (0.00130) | 46.06th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.10% (0.01104) | 54.09th | v2 (v2022.01.01) |
| Sep 17, 2022 | 1.10% (0.01104) | 52.45th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.10% (0.01104) | 50.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.10% (0.01104) | 28.85th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.86% (0.01865) | 48.06th | v1 |
| Jan 6, 2022 | 1.86% (0.01865) | 47.54th | v1 |
| Sep 1, 2021 | 1.86% (0.01865) | 76.13th | v1 |
| Apr 14, 2021 | 1.86% (0.01865) | 0.00th | v1 |
References (12)
- http://www.securityfocus.com/bid/96480 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1037919 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2017-2624 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1424984 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2624 x_refsource_CONFIRMExploitIssue TrackingThird Party Advisory
- https://gitlab.freedesktop.org/xorg/xserver/commit/d7ac755f0b618eb1259d93c8a16ec6e39a18627c x_refsource_CONFIRMPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html mailing-listx_refsource_MLISTThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2017-2624
- https://security.gentoo.org/glsa/201704-03 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://security.gentoo.org/glsa/201710-30 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2017-2624
- https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/ x_refsource_MISCExploitThird Party Advisory
Change history (0)
No recorded changes yet.