CVE-2011-2939: Off-by-one error in the decode_xs function in Unicode/Unicode.xs in the Encode module before 2.44, as used in Perl before 5.15.6, might…
Noroxi assessment
Priority: Monitor (action score 21/100)
- 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: 2.5% (FIRST EPSS); higher than 85.3% of all records.
- Special conditions such as timing or configuration are required.
- Fixed version: libencode-perl (Debian:12) 2.44-1; perl (Debian:12) 5.12.4-4; perl (Red Hat:enterprise_linux:6::server) 4:5.10.1-119.el6_1.1.
Low priority for now. Upgrade to libencode-perl (Debian:12) 2.44-1; perl (Debian:12) 5.12.4-4; perl (Red Hat:enterprise_linux:6::server) 4:5.10.1-119.el6_1.1 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
Off-by-one error in the decode_xs function in Unicode/Unicode.xs in the Encode module before 2.44, as used in Perl before 5.15.6, might allow context-dependent attackers to cause a denial of service (memory corruption) via a crafted Unicode string, which triggers a heap-based buffer overflow.
- Published
- Jan 13, 2012
- Updated
- Jun 16, 2026
- EPSS
- 2.5% · 85th percentile
- CWE
- CWE-189
Report tools
Action score
21
Low priority for now.
- CVSS
- 20 / 40 · 5.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.5%
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.
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- dan kogai encode moduleup to 2.43 inclusive
- dan kogai encode module0.93
- dan kogai encode module0.94
- dan kogai encode module0.95
- dan kogai encode module0.96
- dan kogai encode module0.97
- dan kogai encode module0.98
- dan kogai encode module0.99
+12 more rows
- dan kogai encode module1.00
- dan kogai encode module1.01
- dan kogai encode module1.10
- dan kogai encode module1.11
- dan kogai encode module1.20
- dan kogai encode module1.21
- dan kogai encode module1.25
- dan kogai encode module1.26
- dan kogai encode module1.28
- dan kogai encode module1.30
- dan kogai encode module1.31
- dan kogai encode module1.32
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | libencode-perl | before 2.44-1 | 2.44-1 |
| Debian:12 | perl | before 5.12.4-4 | 5.12.4-4 |
| Red Hat:enterprise_linux:6::server | perl | before 4:5.10.1-119.el6_1.1 | 4:5.10.1-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-Archive-Extract | before 1:0.38-119.el6_1.1 | 1:0.38-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-Archive-Tar | before 0:1.58-119.el6_1.1 | 0:1.58-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-CGI | before 0:3.51-119.el6_1.1 | 0:3.51-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-Compress-Raw-Zlib | before 0:2.023-119.el6_1.1 | 0:2.023-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-Compress-Zlib | before 0:2.020-119.el6_1.1 | 0:2.020-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-core | before 0:5.10.1-119.el6_1.1 | 0:5.10.1-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-CPAN | before 0:1.9402-119.el6_1.1 | 0:1.9402-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-CPANPLUS | before 0:0.88-119.el6_1.1 | 0:0.88-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-debuginfo | before 4:5.10.1-119.el6_1.1 | 4:5.10.1-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-devel | before 4:5.10.1-119.el6_1.1 | 4:5.10.1-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-Digest-SHA | before 1:5.47-119.el6_1.1 | 1:5.47-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-ExtUtils-CBuilder | before 1:0.27-119.el6_1.1 | 1:0.27-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-ExtUtils-Embed | before 0:1.28-119.el6_1.1 | 0:1.28-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-ExtUtils-MakeMaker | before 0:6.55-119.el6_1.1 | 0:6.55-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-ExtUtils-ParseXS | before 1:2.2003.0-119.el6_1.1 | 1:2.2003.0-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-File-Fetch | before 0:0.26-119.el6_1.1 | 0:0.26-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-IO-Compress-Base | before 0:2.020-119.el6_1.1 | 0:2.020-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-IO-Compress-Zlib | before 0:2.020-119.el6_1.1 | 0:2.020-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-IO-Zlib | before 1:1.09-119.el6_1.1 | 1:1.09-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-IPC-Cmd | before 1:0.56-119.el6_1.1 | 1:0.56-119.el6_1.1 |
| Red Hat:enterprise_linux:6::server | perl-libs | before 4:5.10.1-119.el6_1.1 | 4:5.10.1-119.el6_1.1 |
+23
Same product
perl: all recordsOther highest-scoring records for the same primary product.
- CVE-2012-6329The _compile function in Maketext.pm in the Locale::Maketext implementation in Perl before 5.17.7 does not properly handle backslashes and…49Plan
- CVE-2018-18311Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.43Plan
- CVE-2018-18312Perl before 5.26.3 and 5.28.0 before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.43Plan
Published before and after this one in the same product
- ← EarlierCVE-2011-2201Sep 14, 2011 · The Data::FormValidator module 4.66 and earlier for Perl, when untaint_all_constraints is enabled, does not properly preserve the taint…19Monitor
- ← EarlierCVE-2011-3599Oct 10, 2011 · The Crypt::DSA (aka Crypt-DSA) module 1.17 and earlier for Perl, when /dev/random is absent, uses the Data::Random module, which makes it…24Monitor
- Later →CVE-2012-1151Sep 9, 2012 · Multiple format string vulnerabilities in dbdimp.c in DBD::Pg (aka DBD-Pg or libdbd-pg-perl) module before 2.19.0 for Perl allow remote…21Monitor
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:libencode-perl | 2.44-1 · Debian:12 | Package registry (OSV) |
| debian:perl | 5.12.4-4 · Debian:12 | Package registry (OSV) |
| red hat:perl | 4:5.10.1-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-Archive-Extract | 1:0.38-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-Archive-Tar | 0:1.58-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-CGI | 0:3.51-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-Compress-Raw-Zlib | 0:2.023-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-Compress-Zlib | 0:2.020-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-CPAN | 0:1.9402-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-CPANPLUS | 0:0.88-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-Digest-SHA | 1:5.47-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-ExtUtils-CBuilder | 1:0.27-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-ExtUtils-Embed | 0:1.28-119.el6_1.1 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:perl-ExtUtils-MakeMaker | 0:6.55-119.el6_1.1 · Red Hat:enterprise_linux:6::server | 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.
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- P · data can be read
- Integrity
- P · data or configuration can be modified
- Availability
- P · the service can be disrupted
- Attack complexity
- High
- Confidentiality impact
- P
- Integrity impact
- P
- Availability impact
- P
Weakness class (CWE)
CWE-189 · Numeric ErrorsCVSS vector
AV:N/AC:H/Au:N/C:P/I:P/A:P
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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (12 more)Show less
- search.cpan.org/~flora/perl-5.14.2/pod/perldelta.pod#Encode_decode_xs_n-byte_heap-overflow_%28CVE-2011-2939%29
- secunia.com/advisories/46172
- secunia.com/advisories/46989
- secunia.com/advisories/51457
- secunia.com/advisories/55314
- www.mandriva.com/security/advisories?name=MDVSA-2012:008
- www.openwall.com/lists/oss-security/2011/08/18/8
- www.openwall.com/lists/oss-security/2011/08/19/17
- www.redhat.com/support/errata/RHSA-2011-1424.html
- www.securityfocus.com/bid/49858
- www.ubuntu.com/usn/USN-1643-1
- bugzilla.redhat.com/show_bug.cgi?id=731246
Vendor advisories and official records. Exploit/PoC links are deliberately left out.