Integer Overflow
Integer overflow occurs when an arithmetic operation produces a result that exceeds the maximum value a given integer type can store.
How It Works
Integer overflow occurs when an arithmetic operation produces a result that exceeds the maximum value a given integer type can store. In C/C++, this causes the value to "wrap around" to a small number—for example, if a 32-bit unsigned integer at maximum value (4,294,967,295) has 1 added, it wraps to 0. Attackers exploit this by providing carefully crafted input values that, when used in calculations, produce unexpectedly small results.
The most dangerous scenario involves memory allocation. An attacker supplies large values that overflow during size calculations (often when adding header sizes, element counts, or alignment padding), producing a small allocation size. When the program later writes the originally intended large amount of data into this undersized buffer, a heap overflow occurs. For instance: size = user_count * sizeof(struct) + header might overflow if user_count is sufficiently large, resulting in malloc() allocating a tiny buffer that subsequent operations overflow.
Integer overflows also enable logic bypasses. Length checks can be circumvented when overflowed values appear to pass validation. Loop bounds may become incorrect, causing excessive iterations or premature termination. Signed integer overflow (technically undefined behavior in C/C++) can flip positive values to negative, bypassing security checks that assume non-negative numbers.
Impact
- Heap buffer overflow: Undersized allocations lead to memory corruption, enabling arbitrary code execution
- Authentication bypass: Overflowed counters or size checks may skip security validations
- Denial of service: Invalid memory operations cause crashes or infinite loops
- Information disclosure: Incorrect bounds allow reading beyond intended memory regions
- Privilege escalation: Combined with memory corruption, can compromise system integrity
Real-World Examples
The OpenSSH authentication bypass (CVE-2002-0639) involved an integer overflow in challenge-response handling where the number of responses could overflow, allowing authentication bypass. The overflow caused allocation of insufficient memory, which subsequent code exploited to execute arbitrary code.
ImageMagick suffered multiple integer overflow vulnerabilities (CVE-2016-3714 and related) where maliciously crafted image files with extreme dimension values caused size calculations to overflow. This resulted in small heap allocations followed by large writes, enabling remote code execution through image processing.
The Linux kernel's do_brk() function (CVE-2003-0961) contained an integer overflow when calculating memory region sizes. Attackers could wrap the size value to bypass length checks and map memory at arbitrary locations, achieving local privilege escalation.
Mitigation
- Safe arithmetic libraries: Use compiler intrinsics (
__builtin_add_overflow) or libraries (SafeInt, Rust's checked arithmetic) that detect overflow - Pre-calculation validation: Check that operands won't overflow before performing arithmetic operations
- Compiler protections: Enable
-ftrapv(GCC) or/RTCc(MSVC) to trap signed overflow; use UBSan for detection - Use larger types: Perform calculations in 64-bit integers when operands are 32-bit, verify result fits before casting down
- Input validation: Enforce maximum reasonable values on user input before arithmetic
- Modern languages: Use languages with overflow checking (Rust, Swift) or arbitrary precision integers (Python, Java BigInteger)
Recent CVEs (3035)
Integer overflow in the php_filter_encode_url function in ext/filter/sanitizing_filters.c in PHP before 7.0.4 allows remote attackers to cause a denial of service or possibly have unspecified other. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Integer overflow in the xml_utf8_encode function in ext/xml/xml.c in PHP before 7.0.4 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a long. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Integer overflow in the VGA module in QEMU allows local guest OS users to cause a denial of service (out-of-bounds read and QEMU process crash) by editing VGA registers in VBE mode. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
The adreno_perfcounter_query_group function in drivers/gpu/msm/adreno_perfcounter.c in the Adreno GPU driver for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
Integer overflow in the EVP_EncodeUpdate function in crypto/evp/encode.c in OpenSSL before 1.0.1t and 1.0.2 before 1.0.2h allows remote attackers to cause a denial of service (heap memory corruption). Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Epss exploitation probability 45.1%.
Integer overflow in fs/aio.c in the Linux kernel before 3.4.1 allows local users to cause a denial of service or possibly have unspecified other impact via a large AIO iovec. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Integer overflow in the getnum function in lua_struct.c in Redis 2.8.x before 2.8.24 and 3.0.x before 3.0.6 allows context-dependent attackers with permission to run Lua code in a Redis session to. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Multiple integer overflows in the kernel in Apple iOS before 9.3, OS X before 10.11.4, tvOS before 9.2, and watchOS before 2.2 allow attackers to execute arbitrary code in a privileged context via a. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Integer overflow in Adobe Flash Player before 18.0.0.333 and 19.x through 21.x before 21.0.0.182 on Windows and OS X and before 11.2.202.577 on Linux, Adobe AIR before 21.0.0.176, Adobe AIR SDK. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Integer overflow in Adobe Flash Player before 18.0.0.333 and 19.x through 21.x before 21.0.0.182 on Windows and OS X and before 11.2.202.577 on Linux, Adobe AIR before 21.0.0.176, Adobe AIR SDK. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
chan_sip in Asterisk Open Source 1.8.x, 11.x before 11.21.1, 12.x, and 13.x before 13.7.1 and Certified Asterisk 1.8.28, 11.6 before 11.6-cert12, and 13.1 before 13.1-cert3, when the timert1 sip.conf. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. Public exploit code available and no vendor patch available.
Integer overflow in the asf_write_packet function in libavformat/asfenc.c in FFmpeg before 2.8.5 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PCRE before 8.38 mishandles the (?(<digits>) and (?(R<digits>) conditions, which allows remote attackers to cause a denial of service (integer overflow) or possibly have unspecified other impact via. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PCRE before 8.38 mishandles (?123) subroutine calls and related subroutine calls, which allows remote attackers to cause a denial of service (integer overflow) or possibly have unspecified other. Rated high severity (CVSS 7.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Integer underflow in LibreOffice before 4.4.5 and Apache OpenOffice before 4.1.2, when the configuration setting "Load printer settings with the document" is enabled, allows remote attackers to cause. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. Epss exploitation probability 49.6% and no vendor patch available.
Integer overflow in the sg_start_req function in drivers/scsi/sg.c in the Linux kernel 2.6.x through 4.x before 4.1 allows local users to cause a denial of service or possibly have unspecified other. Rated medium severity (CVSS 4.6), this vulnerability is low attack complexity.
Integer overflow in Windows Journal in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT Gold and. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable. Epss exploitation probability 28.0%.
Integer underflow in the base64-decoding implementation in EMC RSA BSAFE Micro Edition Suite (MES) 4.0.x before 4.0.8 and 4.1.x before 4.1.3, RSA BSAFE Crypto-C Micro Edition (Crypto-C ME) before. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Multiple integer overflows in the XML_GetBuffer function in Expat through 2.1.0, as used in Google Chrome before 44.0.2403.89 and other products, allow remote attackers to cause a denial of service. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. No vendor patch available.
Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC Classic before 2015.006.30060, and Acrobat and Acrobat Reader DC Continuous. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable.
Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC Classic before 2015.006.30060, and Acrobat and Acrobat Reader DC Continuous. Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, low attack complexity.
Integer overflow in Adobe Reader and Acrobat 10.x before 10.1.15 and 11.x before 11.0.12, Acrobat and Acrobat Reader DC Classic before 2015.006.30060, and Acrobat and Acrobat Reader DC Continuous. Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, low attack complexity.
The sqlite3VXPrintf function in printf.c in SQLite before 3.8.9 does not properly handle precision and width values during floating-point conversions, which allows context-dependent attackers to. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
Integer overflow in the regcomp implementation in the Henry Spencer BSD regex library (aka rxspencer) alpha3.8.g5 on 32-bit platforms, as used in NetBSD through 6.1.5 and other products, might allow. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. Public exploit code available and EPSS exploitation probability 32.9%.
Multiple integer overflows in potrace 1.11 allow remote attackers to cause a denial of service (crash) via large dimensions in a BMP image, which triggers a buffer overflow. Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Integer overflow in the SkAutoSTArray implementation in include/core/SkTemplates.h in the filters implementation in Skia, as used in Google Chrome before 41.0.2272.76, allows remote attackers to. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer overflow in the crypt_raw method in the key-stretching implementation in jBCrypt before 0.4 makes it easier for remote attackers to determine cleartext values of password hashes via a. Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity.
Integer overflow in Trihedral Engineering VTScada (formerly VTS) 6.5 through 9.x before 9.1.20, 10.x before 10.2.22, and 11.x before 11.1.07 allows remote attackers to cause a denial of service. Rated high severity (CVSS 7.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer overflow in the ProcDRI2GetBuffers function in the DRI2 extension in X.Org Server (aka xserver and xorg-server) 1.7.0 through 1.16.x before 1.16.3 allows remote authenticated users to cause a. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity.
Integer underflow in the ksba_oid_to_str function in Libksba before 1.3.2, as used in GnuPG, allows remote attackers to cause a denial of service (crash) via a crafted OID in a (1) S/MIME message or. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity.
Multiple Integer underflows in the geonet_print function in tcpdump 4.5.0 through 4.6.2, when in verbose mode, allow remote attackers to cause a denial of service (segmentation fault and crash) via a. Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and EPSS exploitation probability 28.3%.
Multiple integer overflows in sound/core/control.c in the ALSA control implementation in the Linux kernel before 3.15.2 allow local users to cause a denial of service by leveraging /dev/snd/controlCX. Rated medium severity (CVSS 4.6), this vulnerability is low attack complexity.
The snd_ctl_elem_add function in sound/core/control.c in the ALSA control implementation in the Linux kernel before 3.15.2 does not properly maintain the user_ctl_count value, which allows local. Rated medium severity (CVSS 4.9), this vulnerability is low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
Multiple integer overflows in the lzo1x_decompress_safe function in lib/lzo/lzo1x_decompress_safe.c in the LZO decompressor in the Linux kernel before 3.15.2 allow context-dependent attackers to. Rated high severity (CVSS 7.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
The (1) BPF_S_ANC_NLATTR and (2) BPF_S_ANC_NLATTR_NEST extension implementations in the sk_run_filter function in net/core/filter.c in the Linux kernel through 3.14.3 do not check whether a certain. Rated medium severity (CVSS 4.9), this vulnerability is low attack complexity. Public exploit code available.
Integer overflow in api.cc in Google V8, as used in Google Chrome before 34.0.1847.131 on Windows and OS X and before 34.0.1847.132 on Linux, allows remote attackers to cause a denial of service or. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer underflow in the pixman_trapezoid_valid macro in pixman.h in Pixman before 0.32.0, as used in X.Org server and cairo, allows context-dependent attackers to cause a denial of service (crash). Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity.
Integer underflow in the xTrapezoidValid macro in render/picture.h in X.Org allows context-dependent attackers to cause a denial of service (crash) via a negative bottom value. Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity.
Integer overflow in the load_image function in file-xwd.c in the X Window Dump (XWD) plug-in in GIMP 2.6.9 and earlier, when used with glib before 2.24, allows remote attackers to cause a denial of. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. No vendor patch available.
Multiple integer overflows in the binary-search implementation in SpiderMonkey in Mozilla Firefox before 26.0 and SeaMonkey before 2.23 might allow remote attackers to cause a denial of service. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer overflow in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1,. Rated medium severity (CVSS 6.9). Public exploit code available.
Integer overflow in the Graphics Device Interface (GDI) in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8,. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable. Epss exploitation probability 71.8%.
Integer overflow in the OZDocument::parseElement function in Apple Motion 5.0.7 allows remote attackers to cause a denial of service (application crash) via a (1) large or (2) small value in the. Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Integer overflow in the valid_user_field function in journal/journald-native.c in systemd allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a large. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Integer overflow in Microsoft Publisher 2003 SP3 allows remote attackers to execute arbitrary code via a crafted Publisher file that triggers an improper allocation-size calculation, aka "Publisher. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable. Epss exploitation probability 64.8% and no vendor patch available.
Integer overflow in Adobe Flash Player before 10.3.183.75 and 11.x before 11.7.700.169 on Windows and Mac OS X, before 10.3.183.75 and 11.x before 11.2.202.280 on Linux, before 11.1.111.50 on Android. Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer overflow in the padding implementation in the opus_packet_parse_impl function in src/opus_decoder.c in Opus before 1.0.2, as used in Google Chrome before 25.0.1364.97 on Windows and Linux and. Rated medium severity (CVSS 5.0), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer overflow in Google Chrome before 25.0.1364.97 on Windows and Linux, and before 25.0.1364.99 on Mac OS X, allows remote attackers to cause a denial of service or possibly have unspecified. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Stack-based buffer overflow in libpixman, as used in Pale Moon before 15.4 and possibly other products, has unspecified impact and context-dependent attack vectors. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Integer overflow in the JavaScript implementation in Mozilla Firefox before 18.0, Firefox ESR 10.x before 10.0.12 and 17.x before 17.0.2, Thunderbird before 17.0.2, Thunderbird ESR 10.x before. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable.
Integer overflow in Google Chrome before 23.0.1271.97 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to PPAPI image buffers. Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Integer overflow in the WebGL subsystem in Mozilla Firefox before 17.0, Firefox ESR 10.x before 10.0.11, Thunderbird before 17.0, Thunderbird ESR 10.x before 10.0.11, and SeaMonkey before 2.14 allows. Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Integer overflow in the ReadImage function in plug-ins/common/file-gif-load.c in the GIF image format plug-in in GIMP 2.8.x and earlier allows remote attackers to cause a denial of service. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. No vendor patch available.
Integer overflow in plug-ins/common/psd.c in the Adobe Photoshop PSD plugin in GIMP 2.2.13 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via a. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. No vendor patch available.
Integer overflow in the queue_init function in unsquashfs.c in unsquashfs in Squashfs 4.2 and earlier allows remote attackers to execute arbitrary code via a crafted block_log field in the superblock. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable. No vendor patch available.
Integer overflow in Adobe Flash Player before 10.3.183.20 and 11.x before 11.3.300.257 on Windows and Mac OS X; before 10.3.183.20 and 11.x before 11.2.202.236 on Linux; before 11.1.111.10 on Android. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable. No vendor patch available.
Integer overflow in the GetEXIFProperty function in magick/property.c in ImageMagick before 6.7.6-4 allows remote attackers to cause a denial of service (out-of-bounds read) via a large component. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Multiple integer overflows in (1) magick/profile.c or (2) magick/property.c in ImageMagick 6.7.5 and earlier allow remote attackers to cause a denial of service (memory corruption) and possibly. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Integer overflow in the drm_mode_dirtyfb_ioctl function in drivers/gpu/drm/drm_crtc.c in the Direct Rendering Manager (DRM) subsystem in the Linux kernel before 3.1.5 allows local users to gain. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Integer overflow in the xfs_acl_from_disk function in fs/xfs/xfs_acl.c in the Linux kernel before 3.1.9 allows local users to cause a denial of service (panic) via a filesystem with a malformed ACL,. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
A critical integer overflow vulnerability exists in GStreamer's gst-plugins-base package before version 0.10.23, allowing remote attackers to execute arbitrary code through specially crafted COVERART tags in Vorbis audio files. The vulnerability triggers when base64-encoded cover art data causes an integer overflow during memory allocation, leading to a heap buffer overflow with full code execution potential. With an EPSS score of 2.82% (86th percentile) and patches available since 2009, this represents a high-severity but dated vulnerability that may still affect legacy systems.
jq, the command-line JSON processor, was patched in Alpine Linux with package version 1.8.2-r0. The specific vulnerability details - including the nature of the flaw, affected upstream jq versions, and precise impact - are not disclosed in the available intelligence. The sole data point is a vendor-sourced fix notification from Alpine Linux, making a full characterization of attacker capability and affected scope impossible at this time.
FreeRDP received a security fix in Alpine Linux package version 3.27.1-r0, addressing an undisclosed vulnerability. The nature, severity, and impact of the underlying flaw are not specified in the available intelligence - no CVE description, CVSS score, CWE classification, or advisory has been published at time of analysis. FreeRDP is an open-source RDP client and server implementation widely used on Linux systems; until further details are disclosed, the risk to affected deployments cannot be quantified.
libssh in Alpine Linux was patched at package version 0.11.2-r0, addressing an unspecified vulnerability tracked as CVE-2025-5449. The nature of the vulnerability - its root cause, attack vector, and impact - is not disclosed in available intelligence sources. The EPSS score of 0.52% (67th percentile) indicates moderate relative ranking among CVEs but low absolute exploitation probability. No active exploitation has been confirmed, and no public exploit code has been identified at time of analysis.
Alpine Linux: mbedtls fixed in 2.28.7-r0