Stack-based buffer overflow in the parseLegacySyslogMsg function in tools/syslogd.c in rsyslogd in rsyslog 4.6.x before 4.6.8 and 5.2.0 thro
Stack-based buffer overflow in the parseLegacySyslogMsg function in tools/syslogd.c in rsyslogd in rsyslog 4.6.x before 4.6.8 and 5.2.0 through 5.8.4 might allow remote attackers to cause a denial of service (application exit) via a long TAG in a legacy syslog message.
- Published
- Sep 6, 2011
- Updated
- Jun 16, 2026
- EPSS
- 20.8% · 97th percentile
- CWE
- CWE-119
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Report tools
Action score
26
Monitor
Low priority for now.
- CVSS
- 20 / 40 · 5.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 6 / 30 · 20.8%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| rsyslog | rsyslog | cpe:2.3:a:rsyslog:rsyslog |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- rsyslog rsyslog4.6.0
- rsyslog rsyslog4.6.1
- rsyslog rsyslog4.6.2
- rsyslog rsyslog4.6.3
- rsyslog rsyslog4.6.4
- rsyslog rsyslog4.6.5
- rsyslog rsyslog4.6.6
- rsyslog rsyslog4.6.7
- rsyslog rsyslog5.2.0
- rsyslog rsyslog5.2.1
- rsyslog rsyslog5.2.2
- rsyslog rsyslog5.3.1
- rsyslog rsyslog5.3.2
- rsyslog rsyslog5.3.3
- rsyslog rsyslog5.3.4
- rsyslog rsyslog5.3.5
- rsyslog rsyslog5.3.6
- rsyslog rsyslog5.3.7
- rsyslog rsyslog5.4.0
- rsyslog rsyslog5.4.1
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | rsyslog | before 5.8.5-1 | 5.8.5-1 |
| openSUSE:Tumbleweed | rsyslog | before 8.23.0-2.1 | 8.23.0-2.1 |
| Red Hat:enterprise_linux:6::server | rsyslog | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
| Red Hat:enterprise_linux:6::server | rsyslog-debuginfo | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
| Red Hat:enterprise_linux:6::server | rsyslog-gnutls | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
| Red Hat:enterprise_linux:6::server | rsyslog-gssapi | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
| Red Hat:enterprise_linux:6::server | rsyslog-mysql | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
| Red Hat:enterprise_linux:6::server | rsyslog-pgsql | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
| Red Hat:enterprise_linux:6::server | rsyslog-relp | before 0:4.6.2-3.el6_1.2 | 0:4.6.2-3.el6_1.2 |
Same product
rsyslog: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-17042An issue was discovered in Rsyslog v8.1908.0.40Plan
- CVE-2019-17041An issue was discovered in Rsyslog v8.1908.0.40Plan
- CVE-2019-17040contrib/pmdb2diag/pmdb2diag.c in Rsyslog v8.1908.0 allows out-of-bounds access because the level length is mishandled.40Plan
- CVE-2017-12588The zmq3 input and output modules in rsyslog before 8.28.0 interpreted description fields as format strings, possibly allowing a format stri40Plan
- CVE-2008-5617The ACL handling in rsyslog 3.12.1 to 3.20.0, 4.1.0, and 4.1.1 does not follow $AllowedSender directive, which allows remote attackers to by35Monitor
- CVE-2022-24903Buffer overflow in TCP syslog server (receiver) components in rsyslog33Monitor
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:rsyslog | 5.8.5-1 · Debian:12 | Package registry (OSV) |
| opensuse:rsyslog | 8.23.0-2.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:rsyslog | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:rsyslog-debuginfo | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:rsyslog-gnutls | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:rsyslog-gssapi | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:rsyslog-mysql | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:rsyslog-pgsql | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
| red hat:rsyslog-relp | 0:4.6.2-3.el6_1.2 · Red Hat:enterprise_linux:6::server | Package registry (OSV) |
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Metasploit module | auxiliary/dos/syslog/rsyslog_long_tagrsyslog Long Tag Off-By-Two DoSauxiliary | 2011-09-01 |
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.
- Metasploit-6 d
- Published
- TodaySep 30, 2026+5503 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- P · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- P
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
AV:N/AC:L/Au:N/C:N/I:N/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.
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
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.adiscon.com/?p=rsyslog.git%3Ba=commit%3Bh=1ca6cc236d1dabf1633238b873fb1c057e52f95e
- lists.fedoraproject.org/pipermail/package-announce/2011-September/065837.html
- lists.fedoraproject.org/pipermail/package-announce/2011-September/065941.html
- lists.opensuse.org/opensuse-updates/2011-09/msg00013.html
- secunia.com/advisories/45922
- secunia.com/advisories/46027
- securitytracker.com/id?1026000
- www.mandriva.com/security/advisories?name=MDVSA-2011:134
- www.redhat.com/support/errata/RHSA-2011-1247.html
- www.rsyslog.com/potential-dos-with-malformed-tag/
- www.securityfocus.com/bid/49413
- bugzilla.redhat.com/show_bug.cgi?id=727644
Vendor advisories and official records. Exploit/PoC links are deliberately left out.