CVE-2011-2721
Description
Off-by-one error in the cli_hm_scan function in matcher-hash.c in libclamav in ClamAV before 0.97.2 allows remote attackers to cause a denial of service (daemon crash) via an e-mail message that is not properly handled during certain hash calculations.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
ClamAV before 0.97.2 has an off-by-one error in cli_hm_scan that allows remote attackers to cause a denial of service via a crafted email.
Vulnerability
An off-by-one error exists in the cli_hm_scan function within matcher-hash.c in libclamav in ClamAV before version 0.97.2. The flaw occurs during hash calculations on email messages, where a specially-crafted hash signature can trigger the off-by-one and lead to a crash. The condition is reachable when scanning messages that contain certain hash values [1][2][3][4].
Exploitation
An attacker can send a crafted email message with a malicious hash signature to a system running an affected version of ClamAV. No authentication or special network position beyond sending the message is required; the service crashes upon processing the malformed input [1][2][3].
Impact
Successful exploitation causes the ClamAV daemon (clamscan) to crash, resulting in a denial of service. The impact is limited to availability; no information disclosure or code execution has been reported [1][2][3][4].
Mitigation
The vulnerability is fixed in ClamAV version 0.97.2, released on 2011-07-26. Users should update to this version or later. Workarounds are not documented; the fix is included in the upstream patch available from the ClamAV git repository [1][2][3][4].
AI Insight generated on May 23, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
119cpe:2.3:a:clamav:clamav:*:*:*:*:*:*:*:*+ 117 more
- cpe:2.3:a:clamav:clamav:*:*:*:*:*:*:*:*range: <=0.97.1
- cpe:2.3:a:clamav:clamav:0.01:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.02:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.03:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.05:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.10:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.12:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.13:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.14:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.14:pre:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.15:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.20:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.21:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.22:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.23:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.24:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.3:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.51:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.52:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.53:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.54:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.60:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.60p:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.65:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.66:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.67:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.67-1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.68:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.68.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.70:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.70:rc:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.71:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.72:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.73:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.74:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.75:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.75.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80:rc:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80_rc:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80:rc2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80:rc3:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.80:rc4:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.81:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.81:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.82:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.83:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.84:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.84:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.84:rc2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.85:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.85.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.86:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.86.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.86.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.86:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.87:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.87.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.3:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.4:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.5:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.6:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.7:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.7_p0:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.88.7_p1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.8:rc3:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.1_p0:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.2_p0:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.3:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.3_p0:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90.3_p1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90:rc1.1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90:rc2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.90:rc3:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.91:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.91.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.91.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.91.2_p0:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.91:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.91:rc2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.92:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.92.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.92_p0:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.93:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.93.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.93.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.93.3:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.94:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.94.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.94.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95.3:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95:rc2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95:src1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.95:src2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96.1:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96.2:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96.3:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96.4:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96.5:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96:rc1:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.96:rc2:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.97:*:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.97:rc:*:*:*:*:*:*
- cpe:2.3:a:clamav:clamav:0.9:rc1:*:*:*:*:*:*
- (no CPE)range: <0.97.2
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
17- www.openwall.com/lists/oss-security/2011/07/26/13nvdPatch
- www.openwall.com/lists/oss-security/2011/07/26/3nvdPatch
- bugzilla.novell.com/show_bug.cginvdPatch
- bugzilla.redhat.com/show_bug.cginvdPatch
- wwws.clamav.net/bugzilla/show_bug.cginvdPatch
- secunia.com/advisories/45382nvdVendor Advisory
- git.clamav.net/gitwebnvd
- lists.fedoraproject.org/pipermail/package-announce/2011-November/068940.htmlnvd
- lists.fedoraproject.org/pipermail/package-announce/2011-November/068941.htmlnvd
- lists.fedoraproject.org/pipermail/package-announce/2011-November/068942.htmlnvd
- secunia.com/advisories/46717nvd
- securitytracker.com/idnvd
- www.mandriva.com/security/advisoriesnvd
- www.osvdb.org/74181nvd
- www.securityfocus.com/bid/48891nvd
- www.ubuntu.com/usn/USN-1179-1nvd
- exchange.xforce.ibmcloud.com/vulnerabilities/68785nvd
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