CWE-134
AllowedUse of Externally-Controlled Format String
Abstraction: Base · Status: Draft
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
530 vulnerabilities reference this CWE, most recent first.
GHSA-7V2R-PPMV-V8G5
Vulnerability from github – Published: 2023-03-05 06:30 – Updated: 2024-02-15 21:31A vulnerability, which was classified as critical, was found in ayttm up to 0.5.0.89. This affects the function http_connect in the library libproxy/proxy.c. The manipulation leads to format string. It is possible to initiate the attack remotely. The name of the patch is 40e04680018614a7d2b68566b261b061a0597046. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-222267.
{
"affected": [],
"aliases": [
"CVE-2015-10088"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-03-05T05:15:00Z",
"severity": "CRITICAL"
},
"details": "A vulnerability, which was classified as critical, was found in ayttm up to 0.5.0.89. This affects the function http_connect in the library libproxy/proxy.c. The manipulation leads to format string. It is possible to initiate the attack remotely. The name of the patch is 40e04680018614a7d2b68566b261b061a0597046. It is recommended to apply a patch to fix this issue. The associated identifier of this vulnerability is VDB-222267.",
"id": "GHSA-7v2r-ppmv-v8g5",
"modified": "2024-02-15T21:31:25Z",
"published": "2023-03-05T06:30:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2015-10088"
},
{
"type": "WEB",
"url": "https://github.com/ayttm/ayttm/commit/40e04680018614a7d2b68566b261b061a0597046"
},
{
"type": "WEB",
"url": "https://sourceforge.net/p/ayttm/mailman/message/34397158"
},
{
"type": "WEB",
"url": "https://vuldb.com/?ctiid.222267"
},
{
"type": "WEB",
"url": "https://vuldb.com/?id.222267"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7XH8-F8CX-FXQ8
Vulnerability from github – Published: 2022-05-01 23:36 – Updated: 2022-05-01 23:36Format string vulnerability in the embedded Internet Explorer component for Mirabilis ICQ 6 build 6043 allows remote servers to execute arbitrary code or cause a denial of service (crash) via unspecified vectors related to HTML code generation.
{
"affected": [],
"aliases": [
"CVE-2008-1120"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-03-03T22:44:00Z",
"severity": "HIGH"
},
"details": "Format string vulnerability in the embedded Internet Explorer component for Mirabilis ICQ 6 build 6043 allows remote servers to execute arbitrary code or cause a denial of service (crash) via unspecified vectors related to HTML code generation.",
"id": "GHSA-7xh8-f8cx-fxq8",
"modified": "2022-05-01T23:36:50Z",
"published": "2022-05-01T23:36:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-1120"
},
{
"type": "WEB",
"url": "http://board.raidrush.ws/showthread.php?t=386983"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/29138"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/28027"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2008/0701"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-7XQ3-XC97-HHR3
Vulnerability from github – Published: 2022-05-24 19:10 – Updated: 2022-05-24 19:10A Format String vulnerablity exists in TRENDnet TEW-755AP 1.11B03, TEW-755AP2KAC 1.11B03, TEW-821DAP2KAC 1.11B03, and TEW-825DAP 1.11B03, which could let a remote malicious user cause a denial of service due to a logic bug at address 0x40dcd0 when calling fprintf with "%s: key len = %d, too long\n" format. The two variables seem to be put in the wrong order. The vulnerability could be triggered by sending the POST request to apply_cgi with a long and unknown key in the request body.
{
"affected": [],
"aliases": [
"CVE-2021-28846"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-08-10T20:15:00Z",
"severity": "MODERATE"
},
"details": "A Format String vulnerablity exists in TRENDnet TEW-755AP 1.11B03, TEW-755AP2KAC 1.11B03, TEW-821DAP2KAC 1.11B03, and TEW-825DAP 1.11B03, which could let a remote malicious user cause a denial of service due to a logic bug at address 0x40dcd0 when calling fprintf with \"%s: key len = %d, too long\\n\" format. The two variables seem to be put in the wrong order. The vulnerability could be triggered by sending the POST request to apply_cgi with a long and unknown key in the request body.",
"id": "GHSA-7xq3-xc97-hhr3",
"modified": "2022-05-24T19:10:31Z",
"published": "2022-05-24T19:10:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-28846"
},
{
"type": "WEB",
"url": "https://github.com/zyw-200/EQUAFL/blob/main/TRENDnet%20ticket.pdf"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-826X-QG76-XQJX
Vulnerability from github – Published: 2026-08-25 15:32 – Updated: 2026-08-31 21:31Issue summary: OpenSSL CMP response validation passed an unexpected response
sender distinguished name directly as the format string to ERR_raise_data().
Impact summary: A malicious or intercepted CMP endpoint can crash a CMP client that enforces an expected sender or uses a pinned server certificate whose subject becomes the default expected sender.
CWE: CWE-134 (Use of Externally-Controlled Format String)
Description: When validating a received CMP message, ossl_cmp_msg_check_update() converts the peer-supplied sender distinguished name with X509_NAME_oneline() and passes it directly as the format argument to ERR_raise_data(). Percent characters survive the conversion, so a sender DN such as "CN=%s%n" reaches BIO_vsnprintf() as an attacker-controlled format string with no matching variadic arguments. This path is only reached when the caller configures an expected sender or pins a server certificate, which is the normal configuration for a CMP client validating server responses.
Since the attacker controls the format string but none of the variadic arguments, such specifiers as %s and %n dereference or write through unrelated stack contents and crash the client. The reliable consequence is a denial of service, when the response comes from a malicious or intercepted CMP endpoint. There is no controlled memory write, arbitrary-address read, or reliable path to remote code execution.
FIPS impact: no
No FIPS modules are affected by this issue, as the CMP protocol implementation is outside the OpenSSL FIPS module boundary.
{
"affected": [],
"aliases": [
"CVE-2026-63073"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-25T13:19:26Z",
"severity": "CRITICAL"
},
"details": "Issue summary: OpenSSL CMP response validation passed an unexpected response\nsender distinguished name directly as the format string to `ERR_raise_data()`.\n\nImpact summary: A malicious or intercepted CMP endpoint can crash a CMP client\nthat enforces an expected sender or uses a pinned server certificate whose\nsubject becomes the default expected sender.\n\nCWE: CWE-134 (Use of Externally-Controlled Format String)\n\nDescription: When validating a received CMP message, ossl_cmp_msg_check_update()\nconverts the peer-supplied sender distinguished name with X509_NAME_oneline()\nand passes it directly as the format argument to ERR_raise_data(). Percent\ncharacters survive the conversion, so a sender DN such as \"CN=%s%n\" reaches\nBIO_vsnprintf() as an attacker-controlled format string with no matching variadic\narguments. This path is only reached when the caller configures an expected\nsender or pins a server certificate, which is the normal configuration for a\nCMP client validating server responses.\n\nSince the attacker controls the format string but none of the variadic\narguments, such specifiers as %s and %n dereference or write through unrelated\nstack contents and crash the client. The reliable consequence is a denial of\nservice, when the response comes from a malicious or intercepted CMP endpoint.\nThere is no controlled memory write, arbitrary-address read, or reliable path\nto remote code execution.\n\nFIPS impact: no\n\nNo FIPS modules are affected by this issue, as the CMP protocol\nimplementation is outside the OpenSSL FIPS module boundary.",
"id": "GHSA-826x-qg76-xqjx",
"modified": "2026-08-31T21:31:51Z",
"published": "2026-08-25T15:32:58Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63073"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/0cc20b322639919aa423e90799d9a57c3b4b76ca"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/6a0acc072b4d37a7cac1252a29c1ce1f00c5ec29"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/7eb2e3ec9d1d4f35c8022fccd4b03398b3f33e21"
},
{
"type": "WEB",
"url": "https://github.com/openssl/openssl/commit/a7e5a6eea8fd3ccca6b6fbba031a5fbf8a3d93b4"
},
{
"type": "WEB",
"url": "https://openssl-library.org/news/secadv/20260825.txt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-83FF-CPF7-GHWF
Vulnerability from github – Published: 2024-02-20 03:30 – Updated: 2025-01-21 21:30A format string vulnerability in a function of the IPSec VPN feature in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, and USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1 could allow an attacker to achieve unauthorized remote code execution by sending a sequence of specially crafted payloads containing an invalid pointer; however, such an attack would require detailed knowledge of an affected device’s memory layout and configuration.
{
"affected": [],
"aliases": [
"CVE-2023-6764"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-20T03:15:07Z",
"severity": "HIGH"
},
"details": "\n\n\n\n\n\n\n\n\n\n\n\nA format string vulnerability in a function of the IPSec VPN feature in Zyxel ATP series firmware versions from 4.32 through 5.37 Patch 1, USG FLEX series firmware versions from 4.50 through 5.37 Patch 1, USG FLEX 50(W) series firmware versions from 4.16 through 5.37 Patch 1, and USG20(W)-VPN series firmware versions from 4.16 through 5.37 Patch 1 could allow an attacker to achieve unauthorized remote code execution by sending a sequence of specially crafted payloads containing an invalid pointer; however, such an attack would require detailed knowledge of an affected device\u2019s memory layout and configuration.\n\n\n\n",
"id": "GHSA-83ff-cpf7-ghwf",
"modified": "2025-01-21T21:30:45Z",
"published": "2024-02-20T03:30:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-6764"
},
{
"type": "WEB",
"url": "https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-multiple-vulnerabilities-in-firewalls-and-aps-02-20-2024"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-84W9-H3XH-WGV5
Vulnerability from github – Published: 2022-10-25 19:00 – Updated: 2022-10-27 19:00Four format string injection vulnerabilities exist in the UPnP logging functionality of Abode Systems, Inc. iota All-In-One Security Kit 6.9Z and 6.9X. A specially-crafted UPnP negotiation can lead to memory corruption, information disclosure, and denial of service. An attacker can host a malicious UPnP service to trigger these vulnerabilities.This vulnerability arises from format string injection via NewInternalClient XML tag, as used within the DoUpdateUPnPbyService action handler.
{
"affected": [],
"aliases": [
"CVE-2022-35880"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-10-25T17:15:00Z",
"severity": "HIGH"
},
"details": "Four format string injection vulnerabilities exist in the UPnP logging functionality of Abode Systems, Inc. iota All-In-One Security Kit 6.9Z and 6.9X. A specially-crafted UPnP negotiation can lead to memory corruption, information disclosure, and denial of service. An attacker can host a malicious UPnP service to trigger these vulnerabilities.This vulnerability arises from format string injection via `NewInternalClient` XML tag, as used within the `DoUpdateUPnPbyService` action handler.",
"id": "GHSA-84w9-h3xh-wgv5",
"modified": "2022-10-27T19:00:32Z",
"published": "2022-10-25T19:00:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-35880"
},
{
"type": "WEB",
"url": "https://talosintelligence.com/vulnerability_reports/TALOS-2022-1583"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-856P-VMG2-WHF5
Vulnerability from github – Published: 2022-05-01 23:39 – Updated: 2022-05-01 23:39Format string vulnerability in Asterisk Open Source 1.6.x before 1.6.0-beta6 might allow remote attackers to execute arbitrary code via logging messages that are not properly handled by (1) the ast_verbose logging API call, or (2) the astman_append function.
{
"affected": [],
"aliases": [
"CVE-2008-1333"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2008-03-20T00:44:00Z",
"severity": "MODERATE"
},
"details": "Format string vulnerability in Asterisk Open Source 1.6.x before 1.6.0-beta6 might allow remote attackers to execute arbitrary code via logging messages that are not properly handled by (1) the ast_verbose logging API call, or (2) the astman_append function.",
"id": "GHSA-856p-vmg2-whf5",
"modified": "2022-05-01T23:39:06Z",
"published": "2022-05-01T23:39:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2008-1333"
},
{
"type": "WEB",
"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/41301"
},
{
"type": "WEB",
"url": "http://downloads.digium.com/pub/security/AST-2008-004.html"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/29426"
},
{
"type": "WEB",
"url": "http://secunia.com/advisories/29456"
},
{
"type": "WEB",
"url": "http://securitytracker.com/id?1019630"
},
{
"type": "WEB",
"url": "http://www.asterisk.org/node/48466"
},
{
"type": "WEB",
"url": "http://www.debian.org/security/2008/dsa-1525"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/archive/1/489823/100/0/threaded"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/28311"
},
{
"type": "WEB",
"url": "http://www.vupen.com/english/advisories/2008/0928"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-86Q3-6WJF-3984
Vulnerability from github – Published: 2022-12-09 18:30 – Updated: 2022-12-14 15:30Crash in the USB HID protocol dissector in Wireshark 3.6.0 to 3.6.8 allows denial of service via packet injection or crafted capture file on Windows
{
"affected": [],
"aliases": [
"CVE-2022-3724"
],
"database_specific": {
"cwe_ids": [
"CWE-134",
"CWE-74"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-12-09T18:15:00Z",
"severity": "HIGH"
},
"details": "Crash in the USB HID protocol dissector in Wireshark 3.6.0 to 3.6.8 allows denial of service via packet injection or crafted capture file on Windows",
"id": "GHSA-86q3-6wjf-3984",
"modified": "2022-12-14T15:30:17Z",
"published": "2022-12-09T18:30:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-3724"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/cves/-/blob/master/2022/CVE-2022-3724.json"
},
{
"type": "WEB",
"url": "https://gitlab.com/wireshark/wireshark/-/issues/18384"
},
{
"type": "WEB",
"url": "https://www.wireshark.org/security/wnpa-sec-2022-08.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-8768-9R9G-5FJ5
Vulnerability from github – Published: 2025-06-06 18:30 – Updated: 2025-06-06 18:30A use of externally-controlled format string vulnerability has been reported to affect Qsync Central. If exploited, the vulnerability could allow remote attackers who have gained user access to obtain secret data or modify memory.
We have already fixed the vulnerability in the following version: Qsync Central 4.5.0.6 ( 2025/03/20 ) and later
{
"affected": [],
"aliases": [
"CVE-2025-22482"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-06T16:15:24Z",
"severity": "LOW"
},
"details": "A use of externally-controlled format string vulnerability has been reported to affect Qsync Central. If exploited, the vulnerability could allow remote attackers who have gained user access to obtain secret data or modify memory.\n\nWe have already fixed the vulnerability in the following version:\nQsync Central 4.5.0.6 ( 2025/03/20 ) and later",
"id": "GHSA-8768-9r9g-5fj5",
"modified": "2025-06-06T18:30:31Z",
"published": "2025-06-06T18:30:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-22482"
},
{
"type": "WEB",
"url": "https://www.qnap.com/en/security-advisory/qsa-25-10"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-88CP-J82V-8FFQ
Vulnerability from github – Published: 2026-07-30 03:31 – Updated: 2026-08-04 15:32A format string vulnerability was found in the Internal Backup on the ADM. The vulnerability occurs because user-controlled task input may be included in an error response and processed through an unsafe format string operation. An authenticated attacker can exploit this issue to disclose memory information or cause denial of service of the affected CGI process. Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RUN1 as well as from ADM 5.0.0 through ADM 5.1.3.RI81.
{
"affected": [],
"aliases": [
"CVE-2026-18187"
],
"database_specific": {
"cwe_ids": [
"CWE-134"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-30T03:16:24Z",
"severity": "HIGH"
},
"details": "A format string vulnerability was found in the Internal Backup on the ADM. The vulnerability occurs because user-controlled task input may be included in an error response and processed through an unsafe format string operation. An authenticated attacker can exploit this issue to disclose memory information or cause denial of service of the affected CGI process.\nAffected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RUN1 as well as from ADM 5.0.0 through ADM 5.1.3.RI81.",
"id": "GHSA-88cp-j82v-8ffq",
"modified": "2026-08-04T15:32:13Z",
"published": "2026-07-30T03:31:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18187"
},
{
"type": "WEB",
"url": "https://www.asustor.com/security/security_advisory_detail?id=67"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
Mitigation
Choose a language that is not subject to this flaw.
Mitigation
Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings. [REF-116] [REF-117]
Mitigation
Run compilers and linkers with high warning levels, since they may detect incorrect usage.
CAPEC-135: Format String Injection
An adversary includes formatting characters in a string input field on the target application. Most applications assume that users will provide static text and may respond unpredictably to the presence of formatting character. For example, in certain functions of the C programming languages such as printf, the formatting character %s will print the contents of a memory location expecting this location to identify a string and the formatting character %n prints the number of DWORD written in the memory. An adversary can use this to read or write to memory locations or files, or simply to manipulate the value of the resulting text in unexpected ways. Reading or writing memory may result in program crashes and writing memory could result in the execution of arbitrary code if the adversary can write to the program stack.
CAPEC-67: String Format Overflow in syslog()
This attack targets applications and software that uses the syslog() function insecurely. If an application does not explicitely use a format string parameter in a call to syslog(), user input can be placed in the format string parameter leading to a format string injection attack. Adversaries can then inject malicious format string commands into the function call leading to a buffer overflow. There are many reported software vulnerabilities with the root cause being a misuse of the syslog() function.