Security readout for executives and security teams
Plain-English summary
CVE-2017-2624 is a timing weakness in Xorg cookie authentication. On affected systems, a local attacker could infer valid MIT cookie bytes and eventually attach to a user’s Xorg session, risking exposure of session data. The sources do not show confirmed active exploitation.
Executive priority
Treat as a targeted local confidentiality risk, not an internet-wide emergency. Prioritize shared Linux workstations, remote desktop hosts, and administrative jump boxes because compromised X sessions can expose sensitive user activity.
Technical view
Xorg xorg-x11-server used memcmp() to compare received MIT cookies with valid cookies. Because memcmp() commonly exits on the first mismatch, response timing can leak partial correctness and make brute forcing more efficient. CVSS 3.0 is 5.9 with local attack vector, high complexity, no privileges required, changed scope, and high confidentiality impact.
Likely exposure
Exposure is most relevant on Linux or Unix systems running affected Xorg/xorg-server packages, especially multi-user desktop or remote graphical environments where untrusted local users can interact with X authentication.
Exploitation context
The bundled record marks KEV as false and provides no cited evidence of exploitation in the wild. The attack is local and high-complexity, but successful abuse could allow attachment to an Xorg session and confidentiality loss.
Researcher notes
Evidence supports a timing side channel in MIT cookie comparison. The record is older, medium severity, and source data is limited to advisory and upstream references. Do not assume remote exploitability, broader products, or active exploitation without additional evidence.
Mitigation direction
- Apply vendor security updates for xorg-server or xorg-x11-server packages.
- Use distribution advisories from Gentoo, Debian, Red Hat, or the relevant OS vendor.
- Confirm whether upstream commit d7ac755f0b618eb1259d93c8a16ec6e39a18627c is included or backported.
- Limit untrusted local shell access on graphical systems until patched.
- Review shared desktop and jump-host systems first.
Validation and detection
- Inventory installed Xorg or xorg-server package versions across Linux desktops and servers.
- Check vendor package changelogs for CVE-2017-2624 or the upstream fix commit.
- Identify systems offering local multi-user access with active Xorg sessions.
- Verify patched systems still use expected X authentication controls.
- Document any unsupported systems requiring compensating access restrictions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-385: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2017-2624 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.9 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N1.44Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.9MediumVector: CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- GLSA-201704-03CVE reference · vendor-advisory, x_refsource_GENTOO
- https://gitlab.freedesktop.org/xorg/xserver/commit/d7ac755f0b618eb1259d93c8a16ec6e39a18627cCVE reference · x_refsource_CONFIRM
- [debian-lts-announce] 20171122 [SECURITY] [DLA 1186-1] xorg-server security updateCVE reference · mailing-list, x_refsource_MLIST
- GLSA-201710-30CVE reference · vendor-advisory, x_refsource_GENTOO
- https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/CVE reference · x_refsource_MISC
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2624CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Covert Timing Channel
Covert Timing Channel represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.