CVE-2011-2895: The LZW decompressor in (1) the BufCompressedFill function in fontfile/decompress.c in X.Org libXfont before 1.4.4 and (2)…
Noroxi assessment
Priority: Plan (action score 40/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 8.3% (FIRST EPSS); higher than 95% of all records.
- Fixed version: libxfont (Debian:12) 1:1.4.4-1; libxfont (Debian:5.0) 1:1.3.3-2; libxfont (Debian:6.0) 1:1.4.1-3.
Add it to your regular patch cycle. Upgrade to libxfont (Debian:12) 1:1.4.4-1; libxfont (Debian:5.0) 1:1.3.3-2; libxfont (Debian:6.0) 1:1.4.1-3 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
The LZW decompressor in (1) the BufCompressedFill function in fontfile/decompress.c in X.Org libXfont before 1.4.4 and (2) compress/compress.c in 4.3BSD, as used in zopen.c in OpenBSD before 3.8, FreeBSD, NetBSD 4.0.x and 5.0.x before 5.0.3 and 5.1.x before 5.1.1, FreeType 2.1.9, and other products, does not properly handle code words that are absent from the decompression table when encountered, which allows context-dependent attackers to trigger an infinite loop or a heap-based buffer overflow, and possibly execute arbitrary code, via a crafted compressed stream, a related issue to CVE-2006-1168 and CVE-2011-2896.
- Published
- Aug 19, 2011
- Updated
- Jun 16, 2026
- EPSS
- 8.3% · 95th percentile
- CWE
- CWE-119
Report tools
Action score
40
Add it to your regular patch cycle.
- CVSS
- 37 / 40 · 9.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 3 / 30 · 8.3%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| x | libxfont | cpe:2.3:a:x:libxfont |
| freetype | freetype | cpe:2.3:a:freetype:freetype |
| freebsd | freebsd | cpe:2.3:o:freebsd:freebsd |
| netbsd | netbsd | cpe:2.3:o:netbsd:netbsd |
| openbsd | openbsd | cpe:2.3:o:openbsd:openbsd |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- freebsd freebsdall versions
- freetype freetype2.1.9
- netbsd netbsdall versions
- openbsd openbsdup to 3.7 inclusive
- openbsd openbsd2.0
- openbsd openbsd2.1
- openbsd openbsd2.2
- openbsd openbsd2.3
+12 more rows
- openbsd openbsd2.4
- openbsd openbsd2.5
- openbsd openbsd2.6
- openbsd openbsd2.7
- openbsd openbsd2.8
- openbsd openbsd2.9
- openbsd openbsd3.0
- openbsd openbsd3.1
- openbsd openbsd3.2
- openbsd openbsd3.3
- openbsd openbsd3.4
- openbsd openbsd3.5
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | libxfont | before 1:1.4.4-1 | 1:1.4.4-1 |
| Debian:5.0 | libxfont | before 1:1.3.3-2 | 1:1.3.3-2 |
| Debian:6.0 | libxfont | before 1:1.4.1-3 | 1:1.4.1-3 |
| Red Hat:enterprise_linux:4::as | freetype | before 0:2.1.9-19.el4 | 0:2.1.9-19.el4 |
| Red Hat:enterprise_linux:4::as | freetype-debuginfo | before 0:2.1.9-19.el4 | 0:2.1.9-19.el4 |
| Red Hat:enterprise_linux:4::as | freetype-demos | before 0:2.1.9-19.el4 | 0:2.1.9-19.el4 |
| Red Hat:enterprise_linux:4::as | freetype-devel | before 0:2.1.9-19.el4 | 0:2.1.9-19.el4 |
| Red Hat:enterprise_linux:4::as | freetype-utils | before 0:2.1.9-19.el4 | 0:2.1.9-19.el4 |
| Red Hat:enterprise_linux:4::as | xorg-x11 | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-deprecated-libs | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-deprecated-libs-devel | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-devel | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-doc | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-font-utils | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-libs | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-Mesa-libGL | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-Mesa-libGLU | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-sdk | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-tools | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-twm | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-xauth | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-xdm | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-Xdmx | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
| Red Hat:enterprise_linux:4::as | xorg-x11-xfs | before 0:6.8.2-1.EL.69 | 0:6.8.2-1.EL.69 |
+11
Same product
x: all recordsOther highest-scoring records for the same primary product.
- CVE-2007-5199A single byte overflow in catalogue.c in X.Org libXfont 1.3.1 allows remote attackers to have unspecified impact.40Plan
- CVE-2013-6462Stack-based buffer overflow in the bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont 1.1 through 1.4.6 allows remote…40Plan
- CVE-2026-56003libXfont2 computeProps Property Buffer Heap Buffer Overflow35Monitor
Published before and after this one in the same product
- Later →CVE-2014-0209May 15, 2014 · Multiple integer overflows in the (1) FontFileAddEntry and (2) lexAlias functions in X.Org libXfont before 1.4.8 and 1.4.9x before…18Monitor
- Later →CVE-2014-0210May 15, 2014 · Multiple buffer overflows in X.Org libXfont before 1.4.8 and 1.4.9x before 1.4.99.901 allow remote font servers to execute arbitrary code…31Monitor
- Later →CVE-2014-0211May 15, 2014 · Multiple integer overflows in the (1) fs_get_reply, (2) fs_alloc_glyphs, and (3) fs_read_extent_info functions in X.Org libXfont before 1.4.31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:libxfont | 1:1.4.4-1 · Debian:12 | Package registry (OSV) |
| red hat:libXfont | 0:1.2.2-1.0.4.el5_7 · Red Hat:enterprise_linux:5::client | Package registry (OSV) |
| red hat:libXfont-debuginfo | 0:1.2.2-1.0.4.el5_7 · Red Hat:enterprise_linux:5::client | Package registry (OSV) |
| red hat:libXfont-devel | 0:1.2.2-1.0.4.el5_7 · Red Hat:enterprise_linux:5::client_workstation | Package registry (OSV) |
| red hat:xorg-x11 | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-deprecated-libs | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-deprecated-libs-devel | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-devel | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-Mesa-libGL | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-Mesa-libGLU | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-Xdmx | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-Xnest | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
| red hat:xorg-x11-Xvfb | 0:6.8.2-1.EL.69 · Red Hat:enterprise_linux:4::as | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
If successful
- Confidentiality
- C · data can be read
- Integrity
- C · data or configuration can be modified
- Availability
- C · the service can be disrupted
- Attack complexity
- M
- Confidentiality impact
- C
- Integrity impact
- C
- Availability impact
- C
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
AV:N/AC:M/Au:N/C:C/I:C/A:C
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2011-007.txt.asc
- lists.apple.com/archives/security-announce/2012/Feb/msg00000.html
- lists.apple.com/archives/security-announce/2012/May/msg00001.html
- lists.apple.com/archives/security-announce/2015/Dec/msg00000.html
- lists.apple.com/archives/security-announce/2015/Dec/msg00001.html
- lists.apple.com/archives/security-announce/2015/Dec/msg00002.html
- lists.apple.com/archives/security-announce/2015/Dec/msg00005.html
- lists.freedesktop.org/archives/xorg-announce/2011-August/001721.html
- lists.freedesktop.org/archives/xorg-announce/2011-August/001722.html
- lists.opensuse.org/opensuse-security-announce/2011-09/msg00019.html
- lists.opensuse.org/opensuse-security-announce/2011-12/msg00004.html
- secunia.com/advisories/45544
- secunia.com/advisories/45568
- secunia.com/advisories/45599
- secunia.com/advisories/45986
- secunia.com/advisories/46127
- secunia.com/advisories/48951
- securitytracker.com/id?1025920
- support.apple.com/kb/HT5130
Vendor advisories and official records. Exploit/PoC links are deliberately left out.