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Fencer Vulns
high 7.5

CVE-2007-4990 in the critical feed json

The swap_char2b function in X.Org X Font Server (xfs) before 1.0.5 allows context-dependent attackers to execute arbitrary code via (1) Que…

published 2007-10-05 19 y ago modified 2026-06-16 4 mo ago also EUVD-2007-4971

cvss
7.5
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
10.7%
EPSS 10.7% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

The swap_char2b function in X.Org X Font Server (xfs) before 1.0.5 allows context-dependent attackers to execute arbitrary code via (1) QueryXBitmaps and (2) QueryXExtents protocol requests with crafted size values that specify an arbitrary number of bytes to be swapped on the heap, which triggers heap corruption.

Patch / fix

  • xorg-x11 RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-sdk RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-twm RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-xdm RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-xfs RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-libs RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-Xdmx RHEL 4 6.8.2-1.EL.33.0.2
  • xorg-x11-Xvfb RHEL 4 6.8.2-1.EL.33.0.2

red hat advisories RHSA-2008:0030RHSA-2008:0029

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2007-4990 updated

xfs heap overflow in the swap_char2b function

  • Red Hat Enterprise Linux 5 xorg-x11-xfs
    affected: no fix planned “Will not fix”
  • Red Hat Desktop version 3 XFree86 4.3.0-126.EL, XFree86-sdk 4.3.0-126.EL, XFree86-twm 4.3.0-126.EL, XFree86-xdm 4.3.0-126.EL, XFree86-xfs 4.3.0-126.EL, XFree86-libs 4.3.0-126.EL, +22 more Red Hat Enterprise Linux AS (Advanced Server) version 2.1 XFree86 4.1.0-86.EL, XFree86-twm 4.1.0-86.EL, XFree86-xdm 4.1.0-86.EL, XFree86-xfs 4.1.0-86.EL, XFree86-libs 4.1.0-86.EL, XFree86-Xvfb 4.1.0-86.EL, +12 more Red Hat Enterprise Linux AS version 3 XFree86 4.3.0-126.EL, XFree86-sdk 4.3.0-126.EL, XFree86-twm 4.3.0-126.EL, XFree86-xdm 4.3.0-126.EL, XFree86-xfs 4.3.0-126.EL, XFree86-libs 4.3.0-126.EL, +22 more
    fixed: vendor fix RHSA-2008:0029
  • Red Hat Enterprise Linux AS version 4 xorg-x11 6.8.2-1.EL.33.0.2, xorg-x11-sdk 6.8.2-1.EL.33.0.2, xorg-x11-twm 6.8.2-1.EL.33.0.2, xorg-x11-xdm 6.8.2-1.EL.33.0.2, xorg-x11-xfs 6.8.2-1.EL.33.0.2, xorg-x11-libs 6.8.2-1.EL.33.0.2, +9 more Red Hat Enterprise Linux Desktop version 4 xorg-x11 6.8.2-1.EL.33.0.2, xorg-x11-sdk 6.8.2-1.EL.33.0.2, xorg-x11-twm 6.8.2-1.EL.33.0.2, xorg-x11-xdm 6.8.2-1.EL.33.0.2, xorg-x11-xfs 6.8.2-1.EL.33.0.2, xorg-x11-libs 6.8.2-1.EL.33.0.2, +9 more
    fixed: vendor fix RHSA-2008:0030
  • Red Hat Enterprise Linux ES version 2.1 XFree86 4.1.0-86.EL, XFree86-twm 4.1.0-86.EL, XFree86-xdm 4.1.0-86.EL, XFree86-xfs 4.1.0-86.EL, XFree86-libs 4.1.0-86.EL, XFree86-Xvfb 4.1.0-86.EL, +12 more Red Hat Enterprise Linux ES version 3 XFree86 4.3.0-126.EL, XFree86-sdk 4.3.0-126.EL, XFree86-twm 4.3.0-126.EL, XFree86-xdm 4.3.0-126.EL, XFree86-xfs 4.3.0-126.EL, XFree86-libs 4.3.0-126.EL, +22 more
    fixed: vendor fix RHSA-2008:0029
  • Red Hat Enterprise Linux ES version 4 xorg-x11 6.8.2-1.EL.33.0.2, xorg-x11-sdk 6.8.2-1.EL.33.0.2, xorg-x11-twm 6.8.2-1.EL.33.0.2, xorg-x11-xdm 6.8.2-1.EL.33.0.2, xorg-x11-xfs 6.8.2-1.EL.33.0.2, xorg-x11-libs 6.8.2-1.EL.33.0.2, +9 more
    fixed: vendor fix RHSA-2008:0030
  • Red Hat Enterprise Linux WS version 2.1 XFree86 4.1.0-86.EL, XFree86-twm 4.1.0-86.EL, XFree86-xdm 4.1.0-86.EL, XFree86-xfs 4.1.0-86.EL, XFree86-libs 4.1.0-86.EL, XFree86-Xvfb 4.1.0-86.EL, +12 more Red Hat Enterprise Linux WS version 3 XFree86 4.3.0-126.EL, XFree86-sdk 4.3.0-126.EL, XFree86-twm 4.3.0-126.EL, XFree86-xdm 4.3.0-126.EL, XFree86-xfs 4.3.0-126.EL, XFree86-libs 4.3.0-126.EL, +22 more
    fixed: vendor fix RHSA-2008:0029
  • Red Hat Enterprise Linux WS version 4 xorg-x11 6.8.2-1.EL.33.0.2, xorg-x11-sdk 6.8.2-1.EL.33.0.2, xorg-x11-twm 6.8.2-1.EL.33.0.2, xorg-x11-xdm 6.8.2-1.EL.33.0.2, xorg-x11-xfs 6.8.2-1.EL.33.0.2, xorg-x11-libs 6.8.2-1.EL.33.0.2, +9 more
    fixed: vendor fix RHSA-2008:0030
  • Red Hat Linux Advanced Workstation 2.1 XFree86 4.1.0-86.EL, XFree86-twm 4.1.0-86.EL, XFree86-xdm 4.1.0-86.EL, XFree86-xfs 4.1.0-86.EL, XFree86-libs 4.1.0-86.EL, XFree86-Xvfb 4.1.0-86.EL, +11 more
    fixed: vendor fix RHSA-2008:0029

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

10.74% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.