Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers to cause a denial of service via an HTTP request w
Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers to cause a denial of service via an HTTP request with an invalid version number, which triggers a reachable assertion in (1) HttpMsg.c and (2) HttpStatusLine.c.
Noroxi analysis
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We use this product, ask for help- Published
- Feb 8, 2009
- Updated
- Jun 16, 2026
- EPSS
- 72.0% · 99th percentile
- CWE
- CWE-20
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Report tools
Action score
42
Plan
Add it to your regular patch cycle.
- CVSS
- 20 / 40 · 5.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 22 / 30 · 72.0%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| squid | squid | cpe:2.3:a:squid:squid |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- squid squid2.7.stable1
- squid squid2.7.stable2
- squid squid2.7.stable3
- squid squid2.7.stable4
- squid squid2.7.stable5
- squid squid3.0.stable1
- squid squid3.0.stable10
- squid squid3.0.stable11
- squid squid3.0.stable12
- squid squid3.0.stable2
- squid squid3.0.stable3
- squid squid3.0.stable4
- squid squid3.0.stable5
- squid squid3.0.stable6
- squid squid3.0.stable7
- squid squid3.0.stable8
- squid squid3.0.stable9
- squid squid3.1
- squid squid3.1.0.1
- squid squid3.1.0.2
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | squid | before 2.7.STABLE3-4.1 | 2.7.STABLE3-4.1 |
| Debian:4.0 | squid3 | before 3.0.PRE5-5+etch1 | 3.0.PRE5-5+etch1 |
Same product
squid: all recordsOther highest-scoring records for the same primary product.
- CVE-2005-0194Squid 2.5, when processing the configuration file, parses empty Access Control Lists (ACLs), including proxy_auth ACLs without defined auth 42Plan
- CVE-2005-0241The httpProcessReplyHeader function in http.c for Squid 2.5-STABLE7 and earlier does not properly set the debug context when it is handling 41Plan
- CVE-2005-0095The WCCP message parsing code in Squid 2.5.STABLE7 and earlier allows remote attackers to cause a denial of service (crash) via malformed WC41Plan
- CVE-2005-0173squid_ldap_auth in Squid 2.5 and earlier allows remote authenticated users to bypass username-based Access Control Lists (ACLs) via a userna40Plan
- CVE-2005-0174Squid 2.5 up to 2.5.STABLE7 allows remote attackers to poison the cache or conduct certain attacks via headers that do not follow the HTTP s35Monitor
- CVE-2002-0163Heap-based buffer overflow in Squid before 2.4 STABLE4, and Squid 2.5 and 2.6 until March 12, 2002 distributions, allows remote attackers to35Monitor
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:squid | 2.7.STABLE3-4.1 · Debian:12 | Package registry (OSV) |
| debian:squid3 | 3.0.PRE5-5+etch1 · Debian:4.0 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Exploit-DB entry ×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 |
|---|---|---|
| Exploit-DB entry | dos | 2009-02-09 |
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.
- Published
- First PoCsame day
- TodaySep 30, 2026+6443 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.
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-20 · Improper Input ValidationCVSS 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
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-security-announce/2009-03/msg00000.html
- secunia.com/advisories/33731
- secunia.com/advisories/34467
- security.gentoo.org/glsa/glsa-200903-38.xml
- www.mandriva.com/security/advisories?name=MDVSA-2009:034
- www.securityfocus.com/archive/1/500653/100/0/threaded
- www.securitytracker.com/id?1021684
- www.squid-cache.org/Advisories/SQUID-2009_1.txt
- www.squid-cache.org/Versions/v2/2.7/changesets/12432.patch
- bugzilla.redhat.com/show_bug.cgi?id=484246
- www.exploit-db.com/exploits/8021
Vendor advisories and official records. Exploit/PoC links are deliberately left out.